LTC2335-16 [Linear]

Buffered Octal, 16-Bit, 200ksps/Ch Differential ±10.24V ADC with 30VP-P Common Mode Range;
LTC2335-16
型号: LTC2335-16
厂家: Linear    Linear
描述:

Buffered Octal, 16-Bit, 200ksps/Ch Differential ±10.24V ADC with 30VP-P Common Mode Range

文件: 总40页 (文件大小:3268K)
中文:  中文翻译
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LTC2358-16  
Buffered Octal, 16-Bit, 200ksps/Ch  
Differential 10.24V ADC with  
30V Common Mode Range  
P-P  
FEATURES  
DESCRIPTION  
TheLTC®2358-16isa16-bit, lownoise8-channelsimulta-  
neous sampling successive approximation register (SAR)  
ADC with buffered differential, wide common mode range  
picoamp inputs. Operating from a 5V low voltage supply,  
flexible high voltage supplies, and using the internal refer-  
enceandbuffer,eachchannelofthisSoftSpanTM ADCcanbe  
independently configured on a conversion-by-conversion  
basis to accept 10.24V, 0V to 10.24V, 5.12V, or 0V to  
5.12V signals. Individual channels may also be disabled  
to increase throughput on the remaining channels.  
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200ksps per Channel Throughput  
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Eight Buffered Simultaneous Sampling Channels  
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500pA/12nA Max Input Leakage at 85°C/125°C  
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1LSB INL (Maximum, 10.24V Range)  
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Guaranteed 16-Bit, No Missing Codes  
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Differential, Wide Common Mode Range Inputs  
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Per-Channel SoftSpan Input Ranges:  
10.24V, 0V to 10.24V, 5.12V, 0V to 5.12V  
12.5V, 0V to 12.5V, 6.25V, 0V to 6.25V  
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94.2dB Single-Conversion SNR (Typical)  
n
−111dB THD (Typical) at f = 2kHz  
128dB CMRR (Typical) at f = 200Hz  
IN  
IN  
The integrated picoamp-input analog buffers, wide input  
commonmoderangeand128dB CMRRoftheLTC2358-16  
allow the ADC to directly digitize a variety of signals us-  
ing minimal board space and power. This input signal  
flexibility, combined with 1LSB INL, no missing codes  
at 16 bits, and 94.2dB SNR, makes the LTC2358-16 an  
ideal choice for many high voltage applications requiring  
wide dynamic range.  
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n
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n
n
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Rail-to-Rail Input Overdrive Tolerance  
Integrated Reference and Buffer (4.096V)  
SPI CMOS (1.8V to 5V) and LVDS Serial I/O  
Internal Conversion Clock, No Cycle Latency  
219mW Power Dissipation (27mW/Ch Typical)  
48-Lead (7mm x 7mm) LQFP Package  
TheLTC2358-16supportspin-selectableSPICMOS(1.8V  
to 5V) and LVDS serial interfaces. Between one and eight  
lanes of data output may be employed in CMOS mode,  
allowing the user to optimize bus width and throughput.  
APPLICATIONS  
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Programmable Logic Controllers  
Industrial Process Control  
Power Line Monitoring  
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All registered trademarks and trademarks are the property of their respective owners. Protected  
by U.S. Patents, including 7705765, 7961132, 8319673, 9197235.  
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Test and Measurement  
TYPICAL APPLICATION  
ꢂꢊꢇ  
ꢀꢁꢂꢃꢄ  
ꢊꢇ  
ꢀꢁꢂꢃꢄ  
ꢂꢁꢆꢇ ꢈꢉ ꢊꢇ  
ꢀꢁꢂꢃꢄ  
Integral Nonlinearity vs  
Output Code and Channel  
ꢅꢁꢅꢃꢄ  
ꢑꢍꢉꢌ ꢉR ꢚꢌ  
ꢝꢖꢉ ꢝꢟꢈꢐRꢄAꢑꢐ  
ꢀꢁꢂꢂ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢀ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃꢄꢅꢆ RAꢇꢈ  
ꢉꢇ  
ꢚꢚ  
ꢛꢘꢄꢄꢐRꢌ  
ꢄꢘꢏꢜ  
ꢚꢝꢄꢄꢐRꢐꢟꢈꢝAꢏ  
ꢠꢊꢇ  
ꢚꢌꢖCMOS  
ꢑꢑ  
ꢚꢚ  
ꢚꢚꢏꢛꢜꢎ  
ꢀRꢁꢂ ꢃꢄꢅꢆꢇAR ꢈRꢄꢉꢂ ꢊꢄꢋ ꢀ ꢁꢂꢃ  
ARꢛꢝꢈRARꢜ  
ꢎꢚ  
ꢝꢟꢀ  
ꢝꢟꢀ  
Aꢀꢀ ꢁꢂAꢃꢃꢄꢀꢅ  
ꢌꢖꢗ  
ꢌꢖꢗ  
ꢌꢖꢗ  
ꢌꢖꢗ  
ꢌꢖꢗ  
ꢌꢖꢗ  
ꢌꢖꢗ  
ꢌꢖꢗ  
ꢠꢂꢀꢇ  
ꢑꢅꢓꢊꢆꢣꢂꢔ  
ꢀꢇ  
ꢀꢇ  
ꢌꢚꢉꢀ  
ꢋꢂꢀꢇ  
ꢋꢊꢇ  
ꢂꢔꢣꢛꢝꢈ  
ꢍꢘꢙ  
ꢌꢚꢉꢢ  
ꢌꢑꢒꢉ  
ꢌꢑꢒꢝ  
ꢌꢚꢝ  
CS  
ꢛꢘꢌꢜ  
ꢑꢟꢇ  
ꢌAR Aꢚꢑ  
ꢘꢟꢝꢎꢉꢏAR  
ꢈRꢘꢐ ꢛꢝꢎꢉꢏAR  
ꢠꢂꢀꢇ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢁ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢃ  
ꢠꢂꢀꢇ  
ꢀꢇ  
ꢀꢇ  
ꢌAꢍꢎꢏꢐ  
ꢑꢏꢉꢑꢒ  
ꢋꢂꢀꢇ  
ꢋꢂꢀꢇ  
ꢝꢟꢢ  
ꢝꢟꢢ  
Rꢐꢄꢛꢘꢄ  
Rꢐꢄꢝꢟ  
ꢞꢟꢚ  
ꢐꢐ  
ꢚꢝꢄꢄꢐRꢐꢟꢈꢝAꢏ ꢝꢟꢎꢘꢈꢌ ꢝꢟ ꢝꢟ ꢡꢝꢈꢗ  
ꢡꢝꢚꢐ ꢝꢟꢎꢘꢈ ꢑꢉꢍꢍꢉꢟ ꢍꢉꢚꢐ RAꢟꢞꢐ  
ꢀꢁꢂꢃꢄꢅ  
ꢀꢁꢂꢃꢄꢅ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢄ  
ꢅꢓꢊꢆꢂꢔ ꢈAꢀꢂꢕ  
ꢀꢁꢂꢃꢁꢂ ꢄꢀꢅꢆ  
ꢤꢢꢃꢄ  
ꢀꢁꢂꢃꢄ  
ꢐꢝꢞꢗꢈ ꢛꢘꢄꢄꢐRꢐꢚ  
ꢌꢝꢍꢘAꢟꢐꢉꢘꢌ  
ꢌAꢍꢎꢏꢝꢟꢞ ꢑꢗAꢟꢟꢐꢏꢌ  
ꢀꢁꢂꢃꢄꢅ ꢆAꢇꢄꢈ  
ꢀꢁꢂꢃꢄ  
ꢋꢂꢊꢇ  
Rev A  
1
Document Feedback  
For more information www.analog.com  
LTC2358-16  
ABSOLUTE MAXIMUM RATINGS  
PIN CONFIGURATION  
(Notes 1, 2)  
ꢝꢛꢖ ꢐꢊꢒꢞ  
Supply Voltage (V ) .....................–0.3V to (V + 40V)  
CC  
EE  
Supply Voltage (V )................................ –17.4V to 0.3V  
EE  
Supply Voltage Difference (V – V )......................40V  
CC  
EE  
Supply Voltage (V )..................................................6V  
DD  
Supply Voltage (OV )................................................6V  
DD  
ꢊꢋꢅ  
ꢊꢋꢅ  
ꢊꢋꢄ  
ꢊꢋꢄ  
ꢊꢋꢃ  
ꢊꢋꢃ  
ꢊꢋꢂ  
ꢊꢋꢂ  
ꢊꢋꢁ  
ꢂꢅ ꢘꢏꢛꢆ  
Internal Regulated Supply Bypass (V  
Analog Input Voltage  
) ... (Note 3)  
DDLBYP  
ꢂꢄ ꢘꢏꢛ ꢙꢘꢏꢛꢅ  
ꢂꢃ ꢘꢏꢛ ꢙꢘꢏꢛꢄ  
ꢂꢂ ꢘꢑꢜꢛ ꢙꢘꢏꢛꢃ  
ꢂꢁ ꢘꢑꢜꢛ ꢙꢘꢑꢜꢛ  
+
+
IN0 to IN7 ,  
ꢂꢀ ꢛꢐ  
ꢏꢏ  
IN0 to IN7 (Note 4) .........(V – 0.3V) to (V + 0.3V)  
EE  
CC  
ꢂꢉ ꢎꢋꢏ  
ꢁꢈ ꢘꢑꢜꢊ ꢙꢘꢑꢜꢊ  
REFIN.................................................... –0.3V to 2.8V  
ꢁꢇ ꢘꢑꢜꢊ ꢙꢘꢏꢛꢂ  
ꢊꢋꢁ ꢀꢉ  
ꢁꢆ ꢘꢏꢊ ꢙꢘꢏꢛꢁ  
REFBUF, CNV (Note 5) ............. –0.3V to (V + 0.3V)  
DD  
DD  
DD  
ꢊꢋꢀ ꢀꢀ  
ꢁꢅ ꢘꢏꢊ ꢙꢘꢏꢛꢀ  
Digital Input Voltage (Note 5)..... –0.3V to (OV + 0.3V)  
ꢊꢋꢀ ꢀꢁ  
ꢁꢄ ꢘꢏꢛꢉ  
Digital Output Voltage (Note 5).. –0.3V to (OV + 0.3V)  
Power Dissipation.............................................. 500mW  
Operating Temperature Range  
LTC2358C................................................ 0°C to 70°C  
LTC2358I .............................................–40°C to 85°C  
LTC2358H.......................................... –40°C to 125°C  
Storage Temperature Range .................. –65°C to 150°C  
ꢗꢟ ꢖAꢑꢜAꢎꢒ  
ꢃꢇꢠꢗꢒAꢏ ꢡꢆꢢꢢ × ꢆꢢꢢꢣ ꢖꢗAꢘꢝꢊꢑ ꢗꢤꢓꢖ  
T
JMAX  
= 150°C, θ = 53°C/W  
JA  
ORDER INFORMATION http://www.linear.com/product/LTC2358-16#orderinfo  
TRAY  
PART MARKING*  
LTC2358LX-16  
LTC2358LX-16  
LTC2358LX-16  
PACKAGE DESCRIPTION  
TEMPERATURE RANGE  
LTC2358CLX-16#PBF  
LTC2358ILX-16#PBF  
LTC2358HLX-16#PBF  
48-Lead (7mm × 7mm) Plastic LQFP  
48-Lead (7mm × 7mm) Plastic LQFP  
48-Lead (7mm × 7mm) Plastic LQFP  
0°C to 70°C  
–40°C to 85°C  
–40°C to 125°C  
Consult ADI Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.  
For more information on lead free part marking, go to: http://www.linear.com/leadfree/  
Rev A  
2
For more information www.analog.com  
LTC2358-16  
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating  
temperature range, otherwise specifications are at TA = 25°C. (Note 6)  
SYMBOL  
V +  
PARAMETER  
CONDITIONS  
MIN  
TYP  
MAX  
UNITS  
l
l
Absolute Input Range  
(Note 7)  
V
V
+ 4  
V
CC  
– 4  
V
IN  
EE  
+
+
(IN0 to IN7 )  
V –  
IN  
Absolute Input Range  
(Note 7)  
+ 4  
V
CC  
– 4  
V
EE  
(IN0 to IN7 )  
l
l
l
l
l
l
l
V + – V – Input Differential Voltage  
SoftSpan 7: 2.5 • V  
SoftSpan 6: 2.5 • V  
Range (Note 7)  
–2.5 V  
2.5 V  
REFBUF  
2.5 V  
REFBUF  
V
V
V
V
V
V
V
IN  
IN  
REFBUF  
REFBUF  
SoftSpan 5: 0V to 2.5 • V  
SoftSpan 4: 0V to 2.5 • V  
REFBUF  
REFBUF  
Range  
/1.024 Range (Note 7)  
–2.5 V  
/1.024  
2.5 V  
/1.024  
REFBUF  
0
0
Range (Note 7)  
REFBUF  
REFBUF  
REFBUF  
REFBUF  
/1.024 Range (Note 7)  
2.5 V  
/1.024  
REFBUF  
SoftSpan 3: 1.25 • V  
SoftSpan 2: 1.25 • V  
SoftSpan 1: 0V to 1.25 • V  
Range (Note 7)  
–1.25 V  
1.25 V  
REFBUF  
REFBUF  
/1.024  
/1.024 Range (Note 7)  
–1.25 V  
1.25 V  
1.25 V  
REFBUF  
/1.024  
REFBUF  
0
REFBUF  
Range (Note 7)  
REFBUF  
l
V
Input Common Mode Voltage (Note 7)  
Range  
V
EE  
+ 4  
V – 4  
CC  
V
CM  
l
V + – V – Input Differential Overdrive  
(Note 8)  
−(V − V  
)
EE  
(V − V  
CC  
)
V
IN  
IN  
CC  
EE  
Tolerance  
l
l
I
Input Overdrive  
V + > V , V – > V (Note 8)  
10  
mA  
mA  
OVERDRIVE  
IN  
IN  
CC IN  
CC  
Current Tolerance  
V + < V , V – < V (Note 8)  
0
IN  
EE IN  
EE  
I
Analog Input Leakage Current  
5
pA  
pA  
nA  
l
l
C-Grade and I-Grade  
H-Grade  
500  
12  
R
Analog Input Resistance  
Analog Input Capacitance  
For Each Pin  
>1000  
3
GΩ  
pF  
IN  
C
IN  
l
CMRR  
Input Common Mode  
Rejection Ratio  
V + = V − = 18V 200Hz Sine  
100  
1.3  
128  
dB  
IN  
IN  
P-P  
l
l
l
V
V
CNV High Level Input Voltage  
CNV Low Level Input Voltage  
CNV Input Current  
V
V
IHCNV  
ILCNV  
INCNV  
0.5  
10  
I
V
= 0V to V  
–10  
μA  
IN  
DD  
CONVERTER CHARACTERISTICS The l denotes the specifications which apply over the full operating  
temperature range, otherwise specifications are at TA = 25°C. (Note 9)  
SYMBOL PARAMETER  
CONDITIONS  
MIN  
16  
TYP  
MAX  
UNITS  
Bits  
l
l
Resolution  
No Missing Codes  
16  
Bits  
Transition Noise  
SoftSpans 7 and 6: 10.24V and 10V Ranges  
SoftSpans 5 and 4: 0V to 10.24V and 0V to 10V Ranges  
SoftSpans 3 and 2: 5.12V and 5V Ranges  
SoftSpan 1: 0V to 5.12V Range  
0.35  
0.7  
0.5  
1.1  
LSB  
RMS  
RMS  
RMS  
RMS  
LSB  
LSB  
LSB  
l
l
l
l
INL  
Integral Linearity Error  
SoftSpans 7 and 6: 10.24V and 10V Ranges (Note 10)  
SoftSpans 5 and 4: 0V to 10.24V and 0V to 10V Ranges (Note 10)  
SoftSpans 3 and 2: 5.12V and 5V Ranges (Note 10)  
SoftSpan 1: 0V to 5.12V Range (Note 10)  
–1  
–1.25  
–1  
0.3  
0.4  
0.4  
0.5  
1
1.25  
1
LSB  
LSB  
LSB  
LSB  
–1.5  
1.5  
l
l
DNL  
ZSE  
Differential Linearity Error (Note 11)  
–0.9  
0.1  
160  
4
0.9  
LSB  
μV  
Zero-Scale Error  
(Note 12)  
–700  
700  
Zero-Scale Error Drift  
Full-Scale Error  
μV/°C  
%FS  
l
FSE  
V
V
= 4.096V (REFBUF Overdriven) (Note 12)  
= 4.096V (REFBUF Overdriven) (Note 12)  
−0.1  
0.025  
2.5  
0.1  
REFBUF  
Full-Scale Error Drift  
ppm/°C  
REFBUF  
Rev A  
3
For more information www.analog.com  
LTC2358-16  
DYNAMIC ACCURACY The l denotes the specifications which apply over the full operating temperature range,  
otherwise specifications are at TA = 25°C. AIN = –1dBFS. (Notes 9, 13)  
SYMBOL PARAMETER  
CONDITIONS  
SoftSpans 7 and 6: 10.24V and 10V Ranges, f = 2kHz  
MIN  
TYP  
MAX  
UNITS  
l
l
l
l
SINAD  
SNR  
Signal-to-(Noise +  
91.5  
86.7  
88.8  
83.5  
94.1  
89.6  
91.6  
86.5  
dB  
dB  
dB  
dB  
IN  
Distortion) Ratio  
SoftSpans 5 and 4: 0V to 10.24V and 0V to 10V Ranges, f = 2kHz  
IN  
SoftSpans 3 and 2: 5.12V and 5V Ranges, f = 2kHz  
IN  
SoftSpan 1: 0V to 5.12V Range, f = 2kHz  
IN  
l
l
l
l
Signal-to-Noise Ratio  
SoftSpans 7 and 6: 10.24V and 10V Ranges, f = 2kHz  
91.7  
86.8  
88.9  
83.6  
94.2  
89.7  
91.6  
86.5  
dB  
dB  
dB  
dB  
IN  
SoftSpans 5 and 4: 0V to 10.24V and 0V to 10V Ranges, f = 2kHz  
IN  
SoftSpans 3 and 2: 5.12V and 5V Ranges, f = 2kHz  
IN  
SoftSpan 1: 0V to 5.12V Range, f = 2kHz  
IN  
l
l
l
l
THD  
Total Harmonic Distortion  
SoftSpans 7 and 6: 10.24V and 10V Ranges, f = 2kHz  
–111  
–107  
–113  
–113  
–101  
–99  
–101  
–100  
dB  
dB  
dB  
dB  
IN  
SoftSpans 5 and 4: 0V to 10.24V and 0V to 10V Ranges, f = 2kHz  
IN  
SoftSpans 3 and 2: 5.12V and 5V Ranges, f = 2kHz  
IN  
SoftSpan 1: 0V to 5.12V Range, f = 2kHz  
IN  
l
l
l
l
SFDR  
Spurious Free Dynamic  
Range  
SoftSpans 7 and 6: 10.24V and 10V Ranges, f = 2kHz  
101  
99  
102  
102  
113  
107  
113  
113  
dB  
dB  
dB  
dB  
IN  
SoftSpans 5 and 4: 0V to 10.24V and 0V to 10V Ranges, f = 2kHz  
IN  
SoftSpans 3 and 2: 5.12V and 5V Ranges, f = 2kHz  
IN  
SoftSpan 1: 0V to 5.12V Range, f = 2kHz  
IN  
Channel-to-Channel  
Crosstalk  
One Channel Converting 18V 200Hz Sine in 10.24V Range,  
−109  
dB  
P-P  
Crosstalk to All Other Channels  
–3dB Input Bandwidth  
Aperture Delay  
6
1
MHz  
ns  
Aperture Delay Matching  
Aperture Jitter  
150  
3
ps  
ps  
RMS  
Transient Response  
Full-Scale Step, 0.005% Settling  
420  
ns  
INTERNAL REFERENCE CHARACTERISTICS The l denotes the specifications which apply over the full  
operating temperature range, otherwise specifications are at TA = 25°C. (Note 9)  
SYMBOL  
PARAMETER  
CONDITIONS  
MIN  
TYP  
2.048  
5
MAX  
2.053  
20  
UNITS  
V
V
REFIN  
Internal Reference Output Voltage  
Internal Reference Temperature Coefficient  
Internal Reference Line Regulation  
Internal Reference Output Impedance  
REFIN Voltage Range  
2.043  
l
(Note 14)  
ppm/°C  
mV/V  
kΩ  
V
DD  
= 4.75V to 5.25V  
0.1  
20  
V
REFIN Overdriven (Note 7)  
1.25  
2.2  
V
REFIN  
REFERENCE BUFFER CHARACTERISTICS  
The l denotes the specifications which apply over the full  
operating temperature range, otherwise specifications are at TA = 25°C. (Note 9)  
SYMBOL  
PARAMETER  
CONDITIONS  
MIN  
4.091  
2.5  
TYP  
MAX  
4.101  
5
UNITS  
l
l
V
Reference Buffer Output Voltage REFIN Overdriven, V  
= 2.048V  
REFIN  
4.096  
V
V
REFBUF  
REFBUF Voltage Range  
REFBUF Input Impedance  
REFBUF Load Current  
REFBUF Overdriven (Notes 7, 15)  
V
REFIN  
= 0V, Buffer Disabled  
13  
kΩ  
l
I
V
V
= 5V, 8 Channels Enabled (Notes 15, 16)  
= 5V, Acquisition or Nap Mode (Note 15)  
1.5  
0.39  
1.9  
mA  
mA  
REFBUF  
REFBUF  
REFBUF  
Rev A  
4
For more information www.analog.com  
LTC2358-16  
DIGITAL INPUTS AND DIGITAL OUTPUTS The l denotes the specifications which apply over the  
full operating temperature range, otherwise specifications are at TA = 25°C. (Note 9)  
SYMBOL  
PARAMETER  
CONDITIONS  
MIN  
0.8 • OV  
–10  
TYP  
MAX  
UNITS  
CMOS Digital Inputs and Outputs  
l
l
l
V
V
High Level Input Voltage  
Low Level Input Voltage  
Digital Input Current  
V
V
IH  
IL  
DD  
0.2 • OV  
10  
DD  
I
V
IN  
= 0V to OV  
DD  
μA  
pF  
V
IN  
C
V
V
Digital Input Capacitance  
High Level Output Voltage  
Low Level Output Voltage  
Hi-Z Output Leakage Current  
Output Source Current  
Output Sink Current  
5
IN  
l
l
l
I
I
= –500μA  
= 500μA  
OV – 0.2  
DD  
OH  
OL  
OUT  
0.2  
10  
V
OUT  
I
I
I
V
OUT  
V
OUT  
V
OUT  
= 0V to OV  
= 0V  
–10  
μA  
mA  
mA  
OZ  
DD  
–50  
50  
SOURCE  
SINK  
= OV  
DD  
LVDS Digital Inputs and Outputs  
l
l
V
Differential Input Voltage  
200  
90  
350  
600  
125  
mV  
ID  
R
On-Chip Input Termination  
Resistance  
CS = 0V, V  
= 1.2V  
106  
10  
Ω
MΩ  
ID  
ICM  
DD  
CS = OV  
l
l
l
l
l
V
Common-Mode Input Voltage  
Common-Mode Input Current  
Differential Output Voltage  
0.3  
–10  
275  
1.1  
1.2  
2.2  
10  
V
μA  
mV  
V
ICM  
I
V + = V – = 0V to OV  
IN IN DD  
ICM  
V
V
R = 100Ω Differential Termination  
L
350  
1.2  
425  
1.3  
10  
OD  
Common-Mode Output Voltage  
Hi-Z Output Leakage Current  
R = 100Ω Differential Termination  
L
OCM  
I
V
OUT  
= 0V to OV  
DD  
–10  
μA  
OZ  
POWER REQUIREMENTS The l denotes the specifications which apply over the full operating temperature  
range, otherwise specifications are at TA = 25°C. (Note 9)  
SYMBOL PARAMETER  
CONDITIONS  
MIN  
7.5  
TYP  
MAX UNITS  
l
l
l
l
V
V
V
V
Supply Voltage  
38  
0
V
V
V
V
CC  
EE  
Supply Voltage  
–16.5  
10  
− V  
Supply Voltage Difference  
Supply Voltage  
38  
CC  
EE  
4.75  
5.00  
5.25  
DD  
VCC  
l
l
l
l
I
Supply Current  
200ksps Sample Rate, 8 Channels Enabled (Note 17)  
Acquisition Mode (Note 17)  
Nap Mode  
4.6  
8.5  
2.9  
6
5.3  
9.8  
3.3  
15  
mA  
mA  
mA  
μA  
Power Down Mode  
l
l
l
l
I
Supply Current  
200ksps Sample Rate, 8 Channels Enabled (Note 17)  
Acquisition Mode (Note 17)  
Nap Mode  
–5.5  
–9.8  
–3.5  
–15  
–4.5  
–8  
–2.8  
–4  
mA  
mA  
mA  
μA  
VEE  
Power Down Mode  
CMOS I/O Mode  
l
OV  
Supply Voltage  
Supply Current  
1.71  
5.25  
V
DD  
l
l
l
l
l
l
I
200ksps Sample Rate, 8 Channels Enabled  
15.6  
13.8  
2.1  
18  
16  
2.7  
2.4  
275  
500  
mA  
mA  
mA  
mA  
μA  
VDD  
200ksps Sample Rate, 8 Channels Enabled, V  
Acquisition Mode  
= 5V (Note 15)  
REFBUF  
Nap Mode  
1.7  
Power Down Mode (C-Grade and I-Grade)  
Power Down Mode (H-Grade)  
106  
106  
µA  
Rev A  
5
For more information www.analog.com  
LTC2358-16  
POWER REQUIREMENTS The l denotes the specifications which apply over the full operating temperature  
range, otherwise specifications are at TA = 25°C. (Note 9)  
SYMBOL PARAMETER  
CONDITIONS  
MIN  
TYP  
MAX UNITS  
l
l
l
I
Supply Current  
200ksps Sample Rate, 8 Channels Enabled (C = 25pF)  
1.7  
1
1
2.6  
20  
20  
mA  
μA  
μA  
OVDD  
L
Acquisition or Nap Mode  
Power Down Mode  
l
l
l
l
l
P
D
Power Dissipation  
200ksps Sample Rate, 8 Channels Enabled  
Acquisition Mode  
219  
258  
94  
0.68  
0.68  
259  
308  
114  
1.9  
3
mW  
mW  
mW  
mW  
mW  
Nap Mode  
Power Down Mode (C-Grade and I-Grade)  
Power Down Mode (H-Grade)  
LVDS I/O Mode  
l
OV  
Supply Voltage  
Supply Current  
2.375  
5.25  
V
DD  
l
l
l
l
l
l
I
200ksps Sample Rate, 8 Channels Enabled  
18.4  
16.8  
3.7  
20.7  
19.2  
4.5  
4.1  
275  
500  
mA  
mA  
mA  
mA  
μA  
VDD  
200ksps Sample Rate, 8 Channels Enabled, V  
Acquisition Mode  
= 5V (Note 15)  
REFBUF  
Nap Mode  
3.4  
Power Down Mode (C-Grade and I-Grade)  
Power Down Mode (H-Grade)  
106  
106  
µA  
l
l
l
I
Supply Current  
200ksps Sample Rate, 8 Channels Enabled (R = 100Ω)  
7
7
1
8.5  
8.0  
20  
mA  
mA  
μA  
OVDD  
L
Acquisition or Nap Mode (R = 100Ω)  
L
Power Down Mode  
l
l
l
l
l
P
D
Power Dissipation  
200ksps Sample Rate, 8 Channels Enabled  
Acquisition Mode  
245  
284  
120  
0.68  
0.68  
287  
337  
143  
1.9  
3
mW  
mW  
mW  
mW  
mW  
Nap Mode  
Power Down Mode (C-Grade and I-Grade)  
Power Down Mode (H-Grade)  
ADC TIMING CHARACTERISTICS The l denotes the specifications which apply over the full operating  
temperature range, otherwise specifications are at TA = 25°C. (Note 9)  
SYMBOL  
PARAMETER  
CONDITIONS  
MIN  
TYP  
MAX  
UNITS  
l
l
l
l
l
l
l
l
f
Maximum Sampling Frequency  
8 Channels Enabled  
7 Channels Enabled  
6 Channels Enabled  
5 Channels Enabled  
4 Channels Enabled  
3 Channels Enabled  
2 Channels Enabled  
1 Channel Enabled  
200  
225  
250  
300  
350  
425  
550  
800  
ksps  
ksps  
ksps  
ksps  
ksps  
ksps  
ksps  
ksps  
SMPL  
l
l
l
l
l
l
l
l
t
Time Between Conversions  
8 Channels Enabled, f  
7 Channels Enabled, f  
6 Channels Enabled, f  
5 Channels Enabled, f  
4 Channels Enabled, f  
3 Channels Enabled, f  
2 Channels Enabled, f  
= 200ksps  
= 225ksps  
= 250ksps  
= 300ksps  
= 350ksps  
= 425ksps  
= 550ksps  
5000  
4444  
4000  
3333  
2855  
2350  
1815  
1250  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
CYC  
SMPL  
SMPL  
SMPL  
SMPL  
SMPL  
SMPL  
SMPL  
1 Channel Enabled, f  
= 800ksps  
SMPL  
l
t
t
Conversion Time  
Acquisition Time  
N Channels Enabled, 1 ≤ N ≤ 8  
450•N  
500•N  
550•N  
ns  
CONV  
ACQ  
l
l
l
l
l
l
l
l
8 Channels Enabled, f  
7 Channels Enabled, f  
6 Channels Enabled, f  
5 Channels Enabled, f  
4 Channels Enabled, f  
3 Channels Enabled, f  
2 Channels Enabled, f  
= 200ksps  
= 225ksps  
= 250ksps  
= 300ksps  
= 350ksps  
= 425ksps  
= 550ksps  
570  
564  
670  
553  
625  
670  
685  
670  
980  
924  
980  
813  
835  
830  
795  
730  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
SMPL  
SMPL  
SMPL  
SMPL  
SMPL  
SMPL  
SMPL  
(t  
= t  
– t  
– t  
)
BUSYLH  
ACQ  
CYC  
CONV  
1 Channel Enabled, f  
= 800ksps  
ns  
SMPL  
Rev A  
6
For more information www.analog.com  
LTC2358-16  
ADC TIMING CHARACTERISTICS The l denotes the specifications which apply over the full operating  
temperature range, otherwise specifications are at TA = 25°C. (Note 9)  
SYMBOL  
PARAMETER  
CONDITIONS  
MIN  
40  
TYP  
MAX  
UNITS  
ns  
l
l
l
l
l
l
t
t
t
t
t
t
t
CNV High Time  
CNVH  
CNVL  
BUSYLH  
QUIET  
PDH  
CNV Low Time  
750  
ns  
CNVto BUSY Delay  
Digital I/O Quiet Time from CNV  
PD High Time  
C = 25pF  
L
30  
ns  
20  
40  
40  
ns  
ns  
PD Low Time  
ns  
PDL  
REFBUF Wake-Up Time  
C
= 47μF, C = 0.1μF  
REFIN  
200  
ms  
WAKE  
REFBUF  
CMOS I/O Mode  
l
l
l
l
l
l
l
l
l
l
l
t
t
t
t
t
t
t
t
t
t
t
SCKI Period  
(Notes 18, 19)  
10  
4
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
SCKI  
SCKI High Time  
SCKIH  
SCKI Low Time  
4
SCKIL  
SDI Setup Time from SCKI  
SDI Hold Time from SCKI  
SDO Data Valid Delay from SCKI  
SDO Remains Valid Delay from SCKI  
SDO to SCKO Skew  
(Note 18)  
(Note 18)  
2
SSDISCKI  
HSDISCKI  
DSDOSCKI  
HSDOSCKI  
SKEW  
1
C = 25pF (Note 18)  
L
7.5  
1
C = 25pF (Note 18)  
L
1.5  
–1  
0
(Note 18)  
0
SDO Data Valid Delay from BUSY  
Bus Enable Time After CS  
Bus Relinquish Time After CS  
C = 25pF (Note 18)  
L
DSDOBUSYL  
EN  
(Note 18)  
(Note 18)  
15  
15  
DIS  
LVDS I/O Mode  
l
l
l
l
l
l
l
l
l
l
l
t
t
t
t
t
t
t
t
t
t
t
SCKI Period  
(Note 20)  
4
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
SCKI  
SCKI High Time  
(Note 20)  
1.5  
1.5  
1.2  
–0.2  
SCKIH  
SCKI Low Time  
(Note 20)  
SCKIL  
SDI Setup Time from SCKI  
SDI Hold Time from SCKI  
SDO Data Valid Delay from SCKI  
SDO Remains Valid Delay from SCKI  
SDO to SCKO Skew  
(Notes 11, 20)  
(Notes 11, 20)  
(Notes 11, 20)  
(Notes 11, 20)  
(Note 11)  
SSDISCKI  
HSDISCKI  
DSDOSCKI  
HSDOSCKI  
SKEW  
6
1
–0.4  
0
0
0.4  
SDO Data Valid Delay from BUSY  
Bus Enable Time After CS  
Bus Relinquish Time After CS  
(Note 11)  
DSDOBUSYL  
EN  
50  
15  
DIS  
Rev A  
7
For more information www.analog.com  
LTC2358-16  
ADC TIMING CHARACTERISTICS  
Note 1: Stresses beyond those listed under Absolute Maximum Ratings  
may cause permanent damage to the device. Exposure to any Absolute  
Maximum Rating condition for extended periods may affect device  
reliability and lifetime.  
Note 11: Guaranteed by design, not subject to test.  
Note 12: For bipolar SoftSpan ranges 7, 6, 3, and 2, zero-scale error is  
the offset voltage measured from –0.5LSB when the output code flickers  
between 0000 0000 0000 0000 and 1111 1111 1111 1111. Full-scale  
error for these SoftSpan ranges is the worst-case deviation of the first and  
last code transitions from ideal and includes the effect of offset error. For  
unipolar SoftSpan ranges 5, 4, and 1, zero-scale error is the offset voltage  
measured from 0.5LSB when the output code flickers between 0000 0000  
0000 0000 and 0000 0000 0000 0001. Full-scale error for these SoftSpan  
ranges is the worst-case deviation of the last code transition from ideal  
and includes the effect of offset error.  
Note 13: All specifications in dB are referred to a full-scale input in the  
relevant SoftSpan input range, except for crosstalk, which is referred to  
the crosstalk injection signal amplitude.  
Note 14: Temperature coefficient is calculated by dividing the maximum  
change in output voltage by the specified temperature range.  
Note 2: All voltage values are with respect to GND.  
Note 3: V  
is the output of an internal voltage regulator, and should  
DDLBYP  
only be connected to a 2.2μF ceramic capacitor to bypass the pin to GND,  
as described in the Pin Functions section. Do not connect this pin to any  
external circuitry.  
Note 4: When these pin voltages are taken below V or above V , they  
EE  
CC  
will be clamped by internal diodes. This product can handle input currents  
of up to 100mA below V or above V without latchup.  
EE  
CC  
Note 5: When these pin voltages are taken below GND or above V or  
DD  
OV , they will be clamped by internal diodes. This product can handle  
DD  
currents of up to 100mA below ground or above V or OV without  
DD  
DD  
latchup.  
Note 15: When REFBUF is overdriven, the internal reference buffer must  
be disabled by setting REFIN = 0V.  
Note 6: –16.5V ≤ V ≤ 0V, 7.5V ≤ V ≤ 38V, 10V ≤ (V – V ) ≤ 38V,  
EE  
CC  
CC  
EE  
V
DD  
= 5V, unless otherwise specified.  
Note 16: I  
active channels.  
varies proportionally with sample rate and the number of  
REFBUF  
Note 7: Recommended operating conditions.  
Note 8: Exceeding these limits on any channel may corrupt conversion  
Note 17: Analog input buffer supply currents from I  
reduced outside the acquisition period. Refer to nap mode in Applications  
Information section.  
and I are  
VCC  
VEE  
results on other channels. Driving an analog input above V on any  
CC  
channel up to 10mA will not affect conversion results on other channels.  
Driving an analog input below V may corrupt conversion results on other  
EE  
channels. Refer to Applications Information section for further details.  
Refer to Absolute Maximum Ratings section for pin voltage limits related  
to device reliability.  
Note 18: Parameter tested and guaranteed at OV = 1.71V, OV = 2.5V,  
DD DD  
and OV = 5.25V.  
DD  
Note 19: A t  
period of 10ns minimum allows a shift clock frequency of  
SCKI  
Note 9: V = 15V, V = –15V, V = 5V, OV = 2.5V, f = 200ksps,  
up to 100MHz for rising edge capture.  
CC  
EE  
DD  
DD  
SMPL  
internal reference and buffer, true bipolar input signal drive in bipolar  
SoftSpan ranges, unipolar signal drive in unipolar SoftSpan ranges, unless  
otherwise specified.  
Note 20: V = 1.2V, V = 350mV for LVDS differential input pairs.  
ICM  
ID  
Note 10: Integral nonlinearity is defined as the deviation of a code from a  
straight line passing through the actual endpoints of the transfer curve.  
The deviation is measured from the center of the quantization band.  
CMOS Timings  
0.8 • OV  
ꢀꢀ  
ꢎꢏꢀꢐꢑ  
0.2 • OV  
ꢀꢀ  
ꢁꢂꢃ  
ꢁꢂꢃ  
ꢀꢋꢌAꢍ  
ꢀꢋꢌAꢍ  
ꢄꢅꢁꢆꢇꢈ ꢉꢂꢇ  
0.8 • OV  
0.2 • OV  
0.8 • OV  
0.2 • OV  
ꢀꢀ  
ꢀꢀ  
ꢀꢀ  
ꢀꢀ  
LVDS Timings (Differential)  
ꢀꢁꢂꢂꢃꢄ  
ꢒꢓꢎꢔꢕ  
ꢅꢁꢂꢂꢃꢄ  
ꢂꢄ  
ꢂꢄ  
ꢎꢏꢐAꢑ  
ꢎꢏꢐAꢑ  
ꢁꢆꢇꢈꢉꢊ ꢋꢂꢉꢌ  
ꢀꢁꢂꢂꢃꢄ  
ꢅꢁꢂꢂꢃꢄ  
ꢀꢁꢂꢂꢃꢄ  
ꢅꢁꢂꢂꢃꢄ  
Figure 1. Voltage Levels for Timing Specifications  
Rev A  
8
For more information www.analog.com  
LTC2358-16  
TA = 25°C, VCC = +15V, VEE = –15V, VDD = 5V,  
TYPICAL PERFORMANCE CHARACTERISTICS  
OVDD = 2.5V, Internal Reference and Buffer (VREFBUF = 4.096V), fSMPL = 200ksps, unless otherwise noted.  
Integral Nonlinearity  
Integral Nonlinearity  
Differential Nonlinearity  
vs Output Code and Channel  
vs Output Code and Channel  
vs Output Code and Channel  
ꢀꢁꢂꢂ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢀ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢂ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢀ  
ꢀꢁꢂꢃ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂꢃꢄꢅꢆ RAꢇꢈ  
ꢀꢁꢂꢃꢄꢅꢆ RAꢇꢈ  
Aꢀꢀ RAꢁꢂꢃꢄ  
Aꢀꢀ ꢁꢂAꢃꢃꢄꢀꢅ  
ꢀRꢁꢂ ꢃꢄꢅꢆꢇAR ꢈRꢄꢉꢂ ꢊꢄꢋ ꢀ ꢁꢂꢃ  
ꢀꢁꢂꢅꢀꢀꢆRꢆꢇꢈꢅAꢂ ꢄRꢅꢉꢆ ꢊꢅꢇ ꢀ ꢁꢂꢃ   
Aꢀꢀ ꢁꢂAꢃꢃꢄꢀꢅ  
Aꢀꢀ ꢁꢂAꢃꢃꢄꢀꢅ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢀ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢁ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢃ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢁ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢃ  
ꢀꢁꢂꢃꢄꢅ  
ꢀꢁꢂꢃꢄꢅ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢄꢅ  
ꢀꢁꢂꢃꢄꢅ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢁꢂꢀ  
ꢀꢁꢂꢃꢁꢂ ꢄꢀꢅꢆ  
ꢀꢁꢂꢃꢁꢂ ꢄꢀꢅꢆ  
ꢀꢁꢂꢃꢁꢂ ꢄꢀꢅꢆ  
ꢀꢁꢂꢃꢄꢅ ꢆꢇꢄ  
ꢀꢁꢂꢃꢄꢅ ꢆꢇꢀ  
ꢀꢁꢂꢃꢄꢅ ꢆꢇꢁ  
Integral Nonlinearity  
vs Output Code and Range  
Integral Nonlinearity  
vs Output Code and Range  
Integral Nonlinearity  
vs Output Code and Range  
ꢀꢁꢂꢂ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢀ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢂ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢀ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢂ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢀ  
ꢀꢁꢂꢃ  
ꢀRꢁꢂ ꢃꢄꢅꢆꢇAR ꢈRꢄꢉꢂ ꢊꢄꢋ ꢀ ꢁꢂꢃ  
ꢀꢁꢂꢅꢀꢀꢆRꢆꢇꢈꢅAꢂ ꢄRꢅꢉꢆ ꢊꢅꢇ ꢀ ꢁꢂꢃ   
ꢀꢁꢂꢃꢄꢅAR ꢆRꢂꢇꢈ ꢉꢂꢁ ꢀ ꢁꢂꢃ  
ꢀꢁꢂ ꢃꢄAꢁꢁꢂꢅ  
ꢀꢁꢂ ꢃꢄAꢁꢁꢂꢅ  
ꢀꢁꢂ ꢃꢄAꢁꢁꢂꢅ  
ꢀꢁꢂꢃꢄꢅꢆ Aꢇꢆ ꢀꢁꢅ  
RAꢀꢁꢂꢃ  
ꢀꢁꢂꢃꢄꢅ Aꢆꢅ ꢀꢄ  
ꢀꢁ ꢂꢃ ꢄꢅꢆꢇꢁ RAꢈꢉꢊ  
RAꢀꢁꢂꢃ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢁ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢃ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢁ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢃ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢁ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢃ  
ꢀꢁꢂꢃꢄꢅ Aꢆꢅ ꢀꢄ  
ꢀꢁꢂꢃꢄꢅꢆ Aꢇꢆ ꢀꢁꢅ  
ꢀꢁ ꢂꢃ ꢄꢀꢅꢆꢇꢁ Aꢈꢉ  
RAꢀꢁꢂꢃ  
RAꢀꢁꢂꢃ  
ꢀꢁ ꢂꢃ ꢄꢀꢁ RAꢅꢆꢇꢈ  
ꢀꢁꢂꢃꢄꢅ  
ꢀꢁꢂꢃꢄꢅ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢄꢅ  
ꢀꢁꢂꢃꢄꢅ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢁꢂꢀ  
ꢀꢁꢂꢃꢁꢂ ꢄꢀꢅꢆ  
ꢀꢁꢂꢃꢁꢂ ꢄꢀꢅꢆ  
ꢀꢁꢂꢃꢁꢂ ꢄꢀꢅꢆ  
ꢀꢁꢂꢃꢄꢅ ꢆꢇꢈ  
ꢀꢁꢂꢃꢄꢅ ꢆꢇꢂ  
ꢀꢁꢂꢃꢄꢅ ꢆꢇꢅ  
Integral Nonlinearity  
vs Output Code  
DC Histogram (Zero-Scale)  
DC Histogram (Near Full-Scale)  
ꢀꢁꢂꢂꢂꢂ  
ꢀꢁꢂꢂꢂꢂ  
ꢀꢁꢂꢂꢂꢂ  
ꢀꢁꢂꢂꢂꢂ  
ꢀꢁꢁꢁꢁꢁ  
ꢀꢁꢁꢁꢁ  
ꢀꢁꢁꢁꢁ  
ꢀꢁꢁꢁꢁ  
ꢀꢁꢁꢁꢁ  
ꢀꢁꢂꢂ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢀ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢂꢂꢂ  
ꢀꢁꢂꢂꢂꢂ  
ꢀꢁꢂꢂꢂꢂ  
ꢀꢁꢂꢂꢂꢂ  
ꢀꢁꢁꢁꢁꢁ  
ꢀꢁꢁꢁꢁ  
ꢀꢁꢁꢁꢁ  
ꢀꢁꢁꢁꢁ  
ꢀꢁꢁꢁꢁ  
ꢀꢁꢂꢃꢄꢅꢆ RAꢇꢈ  
ꢀꢁꢂꢃꢄꢅꢆ RAꢇꢈ  
ꢀꢁꢂꢃꢄꢅꢆ RAꢇꢈ  
ꢀRꢁꢂ ꢃꢄꢅꢆꢇAR ꢈRꢄꢉꢂ ꢊꢄꢋ ꢀ ꢁꢂꢃ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢁ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢃ  
ARꢀꢁꢂRARꢃ ꢄRꢁꢅꢆ  
ꢀꢁ ꢀꢁꢂ ꢀꢁꢂꢂꢁꢃ ꢂꢁꢄꢅ  
ꢀꢁꢂꢃꢄ ꢅꢆꢇꢈꢉꢊꢋ ꢌꢍ ꢆꢇꢈꢉꢊꢋ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢀ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢂ  
ꢀꢁꢂꢃꢄꢅ  
ꢀꢁꢂꢃꢄꢅ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢄ  
ꢀꢁ ꢀꢁ ꢀꢁ ꢀꢁ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃꢁꢂ ꢄꢀꢅꢆ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃꢄꢅ ꢆꢇꢈ  
ꢀꢁꢂꢃꢄꢅ ꢆꢇꢈ  
ꢀꢁꢂꢃꢄꢅ ꢆꢇꢃ  
Rev A  
9
For more information www.analog.com  
LTC2358-16  
TA = 25°C, VCC = +15V, VEE = –15V, VDD = 5V,  
TYPICAL PERFORMANCE CHARACTERISTICS  
OVDD = 2.5V, Internal Reference and Buffer (VREFBUF = 4.096V), fSMPL = 200ksps, unless otherwise noted.  
32k Point Arbitrary Two-Tone FFT  
fSMPL = 200kHz, IN+ = –7dBFS 2kHz  
Sine, IN= –7dBFS 3.1kHz Sine  
32k Point FFT fSMPL = 200kHz,  
fIN = 2kHz  
32k Point FFT fSMPL = 200kHz,  
fIN = 2kHz  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂꢃꢄꢅꢆ RAꢇꢈ  
ꢀꢁꢂꢃꢄꢅꢆ RAꢇꢈ  
ARꢀꢁꢂRARꢃ ꢄRꢁꢅꢆ  
ꢀꢁꢂꢃꢄꢅꢆ RAꢇꢈ  
ꢀRꢁꢂ ꢃꢄꢅꢆꢇAR ꢈRꢄꢉꢂ ꢊꢄꢋ ꢀ ꢁꢂꢃ  
ꢀꢁꢂꢅꢀꢀꢆRꢆꢇꢈꢅAꢂ ꢄRꢅꢉꢆ ꢊꢅꢇ ꢀ ꢁꢂꢃ   
ꢀꢁꢂ  
ꢀꢁR ꢂ ꢃꢄꢅꢆꢇꢈ  
ꢀꢁꢂ ꢃ ꢄꢅꢅꢅꢆꢇ  
ꢀꢁꢂAꢃ ꢄ ꢅꢆꢇꢈꢉꢊ  
ꢀꢁꢂR ꢃ ꢄꢄꢅꢆꢇ  
ꢀꢁꢂ  
ꢀꢁꢂR ꢃ ꢄꢄꢅꢆꢇ  
ꢀꢁR ꢂ ꢃꢄꢅꢆꢇꢈ  
ꢀꢁꢂ  
ꢀꢁR ꢂ ꢃꢄꢅꢆꢇꢈ  
ꢀꢁꢂ ꢃ ꢄꢅꢅꢆꢇꢈ  
ꢀꢁꢂAꢃ ꢄ ꢅꢆꢇꢈꢉꢊ  
ꢀꢁꢂR ꢃ ꢄꢅꢆꢇꢈ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂꢂ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢂ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢂ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃꢄꢅ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁꢁ  
ꢀRꢁꢂꢃꢁꢄꢅꢆ ꢇꢈꢉꢊꢋ  
ꢀRꢁꢂꢃꢁꢄꢅꢆ ꢇꢈꢉꢊꢋ  
ꢀRꢁꢂꢃꢁꢄꢅꢆ ꢇꢈꢉꢊꢋ  
ꢀꢁꢂꢃꢄꢅ ꢆꢄꢇ  
ꢀꢁꢂꢃꢄꢅ ꢆꢄꢀ  
ꢀꢁꢂꢃꢄꢅ ꢆꢄꢄ  
32k Point FFT fSMPL = 200kHz,  
fIN = 2kHz  
SNR, SINAD vs VREFBUF  
,
THD, Harmonics vs VREFBUF  
,
fIN = 2kHz  
fIN = 2kHz  
–105  
–110  
–115  
–120  
–125  
–130  
–135  
ꢀꢁꢂ  
ꢀꢁ  
95  
94  
93  
92  
91  
±2.5 • V  
RANGE  
ꢀꢁꢂꢃꢄꢅ RAꢆꢇ  
REFBUF  
±2.5 • V  
RANGE  
REFBUF  
TRUE BIPOLAR DRIVE (IN = 0V)  
ꢀRꢁꢂ ꢃꢄꢅꢆꢇAR ꢈRꢄꢉꢂ ꢊꢄꢋ ꢀ ꢁꢂꢃ  
TRUE BIPOLAR DRIVE (IN = 0V)  
ꢀꢁꢂ  
ꢀꢁR ꢂ ꢃꢄꢅꢆꢇꢈ  
ꢀꢁꢂ ꢃ ꢄꢅꢅꢆꢇꢈ  
ꢀꢁꢂAꢃ ꢄ ꢅꢆꢇꢈꢉꢊ  
ꢀꢁꢂR ꢃ ꢄꢄꢅꢆꢇ  
ꢀꢁR  
ꢀꢁꢂ  
ꢀꢁꢂAꢃ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂꢂ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂ  
ꢀRꢁ  
2.5  
3
3.5  
4
4.5  
5
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁꢁ  
2.5  
3
3.5  
4
4.5  
5
REFBUF VOLTAGE (V)  
ꢀRꢁꢂꢃꢁꢄꢅꢆ ꢇꢈꢉꢊꢋ  
REFBUF VOLTAGE (V)  
235816 G15  
ꢀꢁꢂꢃꢄꢅ ꢆꢄꢁ  
235816 G14  
SNR, SINAD  
vs Input Frequency  
THD, Harmonics vs Input  
Common Mode, fIN = 2kHz  
THD vs Input Frequency  
ꢀꢁꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂꢃꢄꢅꢆ RAꢇꢈ  
ꢀꢁꢂꢃꢄꢅꢆ RAꢇꢈ  
ꢀꢁ  
ꢀꢁꢀ  
ꢀꢁꢂꢅꢀꢀꢆRꢆꢇꢈꢅAꢂ ꢄRꢅꢉꢆ  
ꢀRꢁꢂ ꢃꢄꢅꢆꢇAR ꢈRꢄꢉꢂ ꢊꢄꢋ ꢀ ꢁꢂꢃ  
ꢀꢁR  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂAꢃ  
ꢀꢁꢂ  
–11V ≤ V ≤ 11V  
1kΩ  
ꢀꢁ  
10kΩ  
ꢀꢁꢂRꢃꢄ  
ꢀꢁꢂ  
ꢀꢁꢂRꢃꢄ  
ꢀꢁꢂꢂ  
ꢀꢁꢁꢂ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢂ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂ  
50Ω SOURCE  
±10.24V RANGE  
TRUE BIPOLAR DRIVE (IN = 0V)  
ꢀRꢁ  
ꢀꢁꢂ  
ꢀꢁ  
ꢀꢁꢁ  
ꢀꢁ  
ꢀꢁꢂ  
ꢀꢁꢁꢂ  
ꢀꢁ  
ꢀꢁꢁ  
ꢀꢁ  
ꢀꢁꢂ  
ꢀꢁꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀRꢁꢂꢃꢁꢄꢅꢆ ꢇꢈꢉꢊ  
ꢀRꢁꢂꢃꢁꢄꢅꢆ ꢇꢈꢉꢊ  
ꢀꢁꢂꢃꢄ ꢅꢆꢇꢇꢆꢁ ꢇꢆꢈꢉ ꢊꢋꢌ  
ꢀꢁꢂꢃꢄꢅ ꢆꢄꢅ  
ꢀꢁꢂꢃꢄꢅ ꢆꢄꢇ  
ꢀꢁꢂꢃꢄꢅ ꢆꢄꢃ  
Rev A  
10  
For more information www.analog.com  
LTC2358-16  
TA = 25°C, VCC = +15V, VEE = –15V, VDD = 5V,  
TYPICAL PERFORMANCE CHARACTERISTICS  
OVDD = 2.5V, Internal Reference and Buffer (VREFBUF = 4.096V), fSMPL = 200ksps, unless otherwise noted.  
SNR, SINAD vs Input Level,  
fIN = 2kHz  
CMRR vs Input Frequency  
and Channel  
Crosstalk vs Input Frequency  
and Channel  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢁ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢀꢁ  
ꢀꢁꢁ  
ꢀꢁ  
ꢀꢁꢂꢃꢄꢅꢆ RAꢇꢈ  
ꢀꢁꢂꢃꢄꢅꢆ RAꢇꢈ  
ꢀRꢁꢂ ꢃꢄꢅꢆꢇAR ꢈRꢄꢉꢂ ꢊꢄꢋ ꢀ ꢁꢂꢃ  
ꢀꢁꢂꢃꢄꢅꢆ RAꢇꢈ  
ꢀꢁ ꢀ ꢁꢂ ꢀ ꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢀ  
ꢀꢁꢂ  
ꢀꢁꢂ ꢀ ꢁꢂ  
Aꢀꢀ ꢁꢂAꢃꢃꢄꢀꢅ  
ꢀꢁꢂ  
ꢀꢁꢂ ꢀ ꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢀ  
Aꢀꢀ ꢁꢂAꢃꢃꢄꢀꢅ ꢁꢆꢃꢇꢄRꢈꢉꢃꢊ  
ꢀꢁꢂ  
ꢀꢁꢂꢂ  
ꢀꢁꢂꢃ  
ꢀꢁꢁꢂ  
ꢀꢁꢁꢂ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂ  
ꢀꢁR  
ꢀꢁꢂAꢃ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁꢂ  
ꢀꢁꢁꢂ ꢀꢁ  
ꢀꢁ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁ  
ꢀꢁꢁ  
ꢀꢁ  
ꢀꢁꢂ  
ꢀꢁ  
ꢀꢁꢁ  
ꢀꢁ  
ꢀꢁꢂ  
ꢀꢁꢁꢂ  
ꢀꢁ  
ꢀꢁꢂꢃꢄ ꢅꢆꢇꢆꢅ ꢈꢉꢊꢋꢌꢍ  
ꢀRꢁꢂꢃꢁꢄꢅꢆ ꢇꢈꢉꢊ  
ꢀRꢁꢂꢃꢁꢄꢅꢆ ꢇꢈꢉꢊ  
ꢀꢁꢂꢃꢄꢅ ꢆꢄꢇ  
ꢀꢁꢂꢃꢄꢅ ꢆꢀꢄ  
ꢀꢁꢂꢃꢄꢅ ꢆꢀꢇ  
SNR, SINAD vs Temperature,  
fIN = 2kHz  
THD, Harmonics vs Temperature,  
fIN = 2kHz  
INL, DNL vs Temperature  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢁ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂ  
ꢀꢁꢂꢂ  
ꢀꢁꢂꢃ  
ꢀꢁꢁꢂ  
ꢀꢁꢁꢂ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢂ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢀ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃꢄꢅꢆ RAꢇꢈ  
ꢀꢁꢂꢃꢄꢅꢆ RAꢇꢈ  
ꢀꢁꢂꢃꢄꢅꢆ RAꢇꢈ  
ꢀRꢁꢂ ꢃꢄꢅꢆꢇAR ꢈRꢄꢉꢂ ꢊꢄꢋ ꢀ ꢁꢂꢃ  
ꢀRꢁꢂ ꢃꢄꢅꢆꢇAR ꢈRꢄꢉꢂ ꢊꢄꢋ ꢀ ꢁꢂꢃ  
ꢀRꢁꢂ ꢃꢄꢅꢆꢇAR ꢈRꢄꢉꢂ ꢊꢄꢋ ꢀ ꢁꢂꢃ  
Aꢀꢀ ꢁꢂAꢃꢃꢄꢀꢅ  
ꢀꢁR  
ꢀAꢁ ꢂꢃꢄ  
ꢀꢁꢂ  
ꢀAꢁ ꢂꢃꢄ  
ꢀꢁꢂAꢃ  
ꢀꢁꢂ  
ꢀꢁꢂ ꢃꢂꢄ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢁ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢃ  
ꢀꢁꢂ ꢁꢂꢃ  
ꢀRꢁ  
ꢀꢁꢁ ꢀꢁꢂ ꢀꢁꢂ  
ꢀꢁ ꢀꢁ ꢀꢁ ꢀꢁ ꢀꢁꢂ ꢀꢁꢂ  
ꢀꢁꢁ ꢀꢁꢂ ꢀꢁꢂ  
ꢀꢁ ꢀꢁ ꢀꢁ ꢀꢁ ꢀꢁꢂ ꢀꢁꢂ  
ꢀꢁꢁ ꢀꢁꢂ ꢀꢁꢂ  
ꢀꢁ ꢀꢁ ꢀꢁ ꢀꢁ ꢀꢁꢂ ꢀꢁꢂ  
ꢀꢁꢂꢃꢁRAꢀꢄRꢁ ꢅꢆꢇꢈ  
ꢀꢁꢂꢃꢁRAꢀꢄRꢁ ꢅꢆꢇꢈ  
ꢀꢁꢂꢃꢁRAꢀꢄRꢁ ꢅꢆꢇꢈ  
ꢀꢁꢂꢃꢄꢅ ꢆꢀꢀ  
ꢀꢁꢂꢃꢄꢅ ꢆꢀꢁ  
ꢀꢁꢂꢃꢄꢅ ꢆꢀꢇ  
Analog Input Leakage  
Current vs Temperature  
Positive Full-Scale Error vs  
Temperature and Channel  
Zero-Scale Error vs  
Temperature and Channel  
ꢀꢁꢂ  
ꢀꢁ  
ꢀꢁꢂꢀꢀ  
ꢀꢁꢀꢂꢃ  
ꢀꢁꢂꢃꢄꢅꢆ RAꢇꢈ  
Rꢀꢁꢂꢃꢁ ꢄꢅꢀRꢆRꢇꢅꢀꢈ  
ꢀꢁꢂꢃꢄꢅꢆ RAꢇꢈ  
Aꢀꢀ ꢁꢂAꢃꢃꢄꢀꢅ  
ꢀꢁ AꢂAꢃꢄꢅ ꢆꢂꢇꢈꢉ ꢇꢆꢂ ꢉRAꢊꢋꢌ  
ꢀꢁR ꢂAꢃꢄ ꢅꢆꢇꢈꢉ ꢊꢁAꢌꢂ  
ꢀ ꢁꢂꢃꢄꢅꢆ  
Rꢀꢁꢂꢃꢁ  
Aꢀꢀ ꢁꢂAꢃꢃꢄꢀꢅ  
ꢀꢁꢀꢂꢀ  
ꢀꢁ ꢂ ꢃꢄ  
ꢀꢁ ꢂ ꢃꢄꢅꢆ  
ꢀꢁ ꢂ ꢃꢄꢅꢆ  
ꢀꢁꢀꢂꢃ  
ꢀꢁꢁ  
ꢀꢁ  
ꢀꢁꢀꢀꢀ  
ꢀꢁꢂꢁꢃꢄ  
ꢀꢁꢂꢁꢃꢁ  
ꢀꢁꢂꢁꢃꢄ  
ꢀꢁꢂꢃꢁꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁꢂ  
ꢀꢁꢁ ꢀꢁꢂ ꢀꢁꢂ  
ꢀꢁ ꢀꢁ ꢀꢁ ꢀꢁ ꢀꢁꢂ ꢀꢁꢂ  
ꢀꢁꢁ ꢀꢁꢂ ꢀꢁꢂ  
ꢀꢁ ꢀꢁ ꢀꢁ ꢀꢁ ꢀꢁꢂ ꢀꢁꢂ  
ꢀꢁꢁ ꢀꢁꢂ ꢀꢁꢂ  
ꢀꢁ ꢀꢁ ꢀꢁ ꢀꢁ ꢀꢁꢂ ꢀꢁꢂ  
ꢀꢁꢂꢃꢁRAꢀꢄRꢁ ꢅꢆꢇꢈ  
ꢀꢁꢂꢃꢁRAꢀꢄRꢁ ꢅꢆꢇꢈ  
ꢀꢁꢂꢃꢁRAꢀꢄRꢁ ꢅꢆꢇꢈ  
ꢀꢁꢂꢃꢄꢅ ꢆꢀꢂ  
ꢀꢁꢂꢃꢄꢅ ꢆꢀꢅ  
ꢀꢁꢂꢃꢄꢅ ꢆꢀꢇ  
Rev A  
11  
For more information www.analog.com  
LTC2358-16  
TA = 25°C, VCC = +15V, VEE = –15V, VDD = 5V,  
TYPICAL PERFORMANCE CHARACTERISTICS  
OVDD = 2.5V, Internal Reference and Buffer (VREFBUF = 4.096V), fSMPL = 200ksps, unless otherwise noted.  
Power-Down Current  
vs Temperature  
Supply Current vs Temperature  
PSRR vs Frequency  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁꢁꢁ  
ꢀꢁꢁ  
ꢀꢁ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢀꢁ  
ꢀꢁꢁ  
ꢀꢁ  
ꢀꢁ ꢀ ꢁꢂ ꢀ ꢁꢂ  
ꢀꢁꢁ  
ꢀꢀ  
ꢀꢁꢁ  
ꢀꢁ  
ꢀꢀ  
ꢀꢁꢁ  
ꢀꢀ  
ꢀꢁꢁ  
ꢀꢁ  
ꢀꢁꢁ  
ꢀꢁꢂꢂ  
ꢀꢁ  
ꢀꢁꢂ  
ꢀꢁꢀꢂ  
ꢀꢁ  
ꢀꢁꢂꢂ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁꢁ  
ꢀꢀ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁꢁ ꢀꢁꢂ ꢀꢁꢂ  
ꢀꢁ ꢀꢁ ꢀꢁ ꢀꢁ ꢀꢁꢂ ꢀꢁꢂ  
ꢀꢁꢁ ꢀꢁꢂ ꢀꢁꢂ  
ꢀꢁ ꢀꢁ ꢀꢁ ꢀꢁ ꢀꢁꢂ ꢀꢁꢂ  
ꢀꢁ  
ꢀꢁꢁ  
ꢀꢁ  
ꢀꢁꢂ  
ꢀꢁꢁꢂ  
ꢀꢁꢂꢃꢁRAꢀꢄRꢁ ꢅꢆꢇꢈ  
ꢀꢁꢂꢃꢁRAꢀꢄRꢁ ꢅꢆꢇꢈ  
ꢀRꢁꢂꢃꢁꢄꢅꢆ ꢇꢈꢉꢊ  
ꢀꢁꢂꢃꢄꢅ ꢆꢀꢃ  
ꢀꢁꢂꢃꢄꢅ ꢆꢀꢇ  
ꢀꢁꢂꢃꢄꢅ ꢆꢁꢇ  
Offset Error  
vs Input Common Mode  
Internal Reference Output  
vs Temperature  
Supply Current vs Sampling Rate  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢂ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢄ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂꢃ ꢄAꢅ ꢆꢇꢈꢉ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃꢄꢅꢆ RAꢇꢈ  
ꢀꢁ ꢂꢃꢄꢅꢆ  
ꢀ ꢁꢂꢃ  
ꢀꢁꢁ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀ ꢁꢂ ꢄ ꢃ ꢀ ꢁꢂ  
ꢀꢀ  
ꢀꢁ  
ꢀꢀ  
ꢀꢁꢁ  
ꢀ ꢁꢂ ꢃꢄ ꢅꢁꢂ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢂ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀ ꢁꢂꢃꢄ ꢆ ꢅ ꢀ ꢁꢂꢃꢄꢅꢆ  
ꢀ ꢁꢂꢃꢄꢅꢆ ꢇꢈ ꢂꢉꢄꢅꢆ  
ꢀꢀ  
ꢀꢀ  
ꢀꢁꢁ  
ꢀꢁꢁ ꢀꢁꢂ ꢀꢁꢂ  
ꢀꢁ ꢀꢁ ꢀꢁ ꢀꢁ ꢀꢁꢂ ꢀꢁꢂ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢁ  
ꢀꢁꢂ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁꢂꢃꢁRAꢀꢄRꢁ ꢅꢆꢇꢈ  
ꢀAꢁꢂꢃꢄꢅꢆ ꢇRꢈꢉꢊꢈꢅꢋꢌ ꢍꢎꢏꢐꢑ  
ꢀꢁꢂꢃꢄ ꢅꢆꢇꢇꢆꢁ ꢇꢆꢈꢉ ꢊꢋꢌ  
ꢀꢁꢂꢃꢄꢅ ꢆꢁꢀ  
ꢀꢁꢂꢃꢄꢅ ꢆꢁꢁ  
ꢀꢁꢂꢃꢄꢅ ꢆꢁꢄ  
Power Dissipation vs Sampling  
Rate, N-Channels Enabled  
Step Response  
(Large-Signal Settling)  
Step Response  
(Fine Settling)  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢀꢁ  
ꢀꢁꢁ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢁ  
ꢀꢁ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃ  
ꢀꢁꢁ  
ꢀꢁ  
ꢀꢁꢂꢃꢄꢅꢆ RAꢇꢈ  
ꢀ ꢁ ꢂ  
ꢀꢁ ꢀ ꢁꢂꢂꢃꢂꢂꢂꢄꢅꢆꢇꢈ  
ꢀ ꢁ ꢂ  
ꢀꢁꢂARꢃ ꢄAꢅꢃ  
ꢀꢁ  
ꢀ ꢁ ꢂ  
ꢀꢁ ꢀ ꢁꢂ  
ꢀ ꢁ ꢂ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁꢂꢃꢄꢅꢆ RAꢇꢈ  
ꢀꢁ ꢀ ꢁꢂꢂꢃꢂꢂꢂꢄꢅꢆꢇꢈ ꢉꢊꢋARꢌ ꢍAꢎꢌ  
ꢀꢁ ꢀ ꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂꢂ  
ꢀꢁꢂꢃꢄ  
ꢀꢁꢂꢃꢄꢅ  
ꢀꢁꢂꢃꢄꢅ  
ꢀꢁꢂꢃꢄꢅ  
ꢀꢁꢂꢃ ꢄAꢅ ꢆꢇꢈꢉ  
ꢀ ꢁꢂꢃꢄꢅ  
ꢀꢁꢂꢃ  
ꢀꢁꢁ ꢀꢁꢁ ꢀꢁꢁ ꢀꢁꢁ ꢀꢁꢁ ꢀꢁꢁ ꢀꢁꢁ ꢀꢁꢁ  
ꢀꢁꢂꢂ  
ꢀꢁꢁ ꢀꢁꢁ ꢀꢁꢁ ꢀꢁꢁ ꢀꢁꢁ ꢀꢁꢁ ꢀꢁꢁ ꢀꢁꢁ ꢀꢁꢁ  
ꢀꢁꢂꢂ  
ꢀꢁꢁ ꢀꢁꢁ ꢀꢁꢁ ꢀꢁꢁ ꢀꢁꢁ ꢀꢁꢁ ꢀꢁꢁ ꢀꢁꢁ ꢀꢁꢁ  
ꢀAꢁꢂꢃꢄꢅꢆ ꢇRꢈꢉꢊꢈꢅꢋꢌ ꢍꢎꢏꢐꢑ  
ꢀꢁꢂꢂꢃꢄꢅꢆ ꢂꢄꢇꢁ ꢈꢉꢊꢋ  
ꢀꢁꢂꢂꢃꢄꢅꢆ ꢂꢄꢇꢁ ꢈꢉꢊꢋ  
ꢀꢁꢂꢃꢄꢅ ꢆꢁꢇ  
ꢀꢁꢂꢃꢄꢅ ꢆꢁꢂ  
ꢀꢁꢂꢃꢄꢅ ꢆꢁꢅ  
Rev A  
12  
For more information www.analog.com  
LTC2358-16  
PIN FUNCTIONS  
Pins that are the Same for All Digital I/O Modes  
REFIN. With the buffer disabled, overdrive REFBUF with  
an external reference voltage in the range of 2.5V to 5V.  
When using the internal reference buffer, limit the loading  
of any external circuitry connected to REFBUF to less than  
200µA. Using a high input impedance amplifier to buffer  
+
+
IN0 /IN0 toIN7 /IN7 (Pins14/13,12/11,10/9,8/7,6/5,  
4/3,2/1,and48/47):PositiveandNegativeAnalogInputs,  
Channels 0 to 7. The converter simultaneously samples  
and digitizes (V + – V –) for all channels. Wide input  
common mode range (V + 4V ≤ V ≤ V – 4V) and  
IN  
IN  
EE  
V
to any external circuits is recommended.  
REFBUF  
CM  
CC  
high common mode rejection allow the inputs to accept  
a wide variety of signal swings. Full-scale input range is  
determined by the channel’s SoftSpan configuration.  
PD (Pin 22): Power Down Input. When this pin is brought  
high, the LTC2358-16 is powered down and subsequent  
conversion requests are ignored. If this occurs during a  
conversion, the device powers down once the conversion  
completes. If this pin is brought high twice without an  
intervening conversion, an internal global reset is initi-  
ated, equivalent to a power-on-reset event. Logic levels  
GND (Pins 15, 18, 20, 30, 41, 44, 46): Ground. Solder  
all GND pins to a solid ground plane.  
V
(Pin 16): Positive High Voltage Power Supply. The  
CC  
range of V is 7.5V to 38V with respect to GND and 10V  
are determined by OV .  
CC  
DD  
to 38V with respect to V . Bypass V to GND close to  
the pin with a 0.1μF ceramic capacitor.  
EE  
CC  
LVDS/CMOS(Pin23):I/OModeSelect.TiethispintoOV  
DD  
to select LVDS I/O mode, or to ground to select CMOS I/O  
V
(Pins 17, 45): Negative High Voltage Power Supply.  
mode. Logic levels are determined by OV .  
EE  
DD  
The range of V is 0V to –16.5V with respect to GND and  
EE  
CNV (Pin 24): Conversion Start Input. A rising edge on  
this pin puts the internal sample-and-holds into the hold  
mode and initiates a new conversion. CNV is not gated  
by CS, allowing conversions to be initiated independent  
of the state of the serial I/O bus.  
–10V to –38V with respect to V . Connect Pins 17 and 45  
CC  
together and bypass the V network to GND close to Pin  
EE  
17 with a 0.1μF ceramic capacitor. In applications where  
V
EE  
is shorted to GND, this capacitor may be omitted.  
REFIN(Pin19):BandgapReferenceOutput/ReferenceBuf-  
ferInput.Aninternalbandgapreferencenominallyoutputs  
2.048V on this pin. An internal reference buffer amplifies  
BUSY (Pin 38): Busy Output. The BUSY signal indicates  
that a conversion is in progress. This pin transitions low-  
to-high at the start of each conversion and stays high until  
the conversion is complete. Logic levels are determined  
V
V
to create the converter master reference voltage  
REFIN  
= 2 • V  
on the REFBUF pin. When using the  
REFBUF  
REFIN  
by OV .  
DD  
internal reference, bypass REFIN to GND (Pin 20) close to  
thepinwitha0.1μFceramiccapacitortofilterthebandgap  
outputnoise. Ifmoreaccuracyisdesired, overdriveREFIN  
with an external reference in the range of 1.25V to 2.2V.  
Do not load this pin when internal reference is used.  
V
(Pin40):Internal2.5VRegulatorBypassPin. The  
DDLBYP  
voltage on this pin is generated via an internal regulator  
operating off of V . This pin must be bypassed to GND  
DD  
close to the pin with a 2.2μF ceramic capacitor. Do not  
connect this pin to any external circuitry.  
REFBUF (Pin 21): Internal Reference Buffer Output. An  
internal reference buffer amplifies V  
converter master reference voltage V  
to create the  
V
(Pins 42, 43): 5V Power Supply. The range of V  
DD DD  
REFIN  
= 2 • V  
is 4.75V to 5.25V. Connect Pins 42 and 43 together and  
REFBUF  
REFIN  
on this pin, nominally 4.096V when using the internal  
bandgapreference. BypassREFBUF to GND(Pin 20)close  
to the pin with a 47μF ceramic capacitor. The internal ref-  
erence buffer may be disabled by grounding its input at  
bypass the V network to GND with a shared 0.1μF  
ceramic capacitor close to the pins.  
DD  
Rev A  
13  
For more information www.analog.com  
LTC2358-16  
PIN FUNCTIONS  
CMOS I/O Mode  
LVDS I/O Mode  
SDO0 to SDO7 (Pins 25, 26, 27, 28, 33, 34, 35, and 36):  
CMOS Serial Data Outputs, Channels 0 to 7. The most  
recent conversion result along with channel configuration  
information is clocked out onto the SDO pins on each ris-  
ing edge of SCKI. Output data formatting is described in  
the Digital Interface section. Leave unused SDO outputs  
SDO0, SDO7, SDI (Pins 25, 36, and 37): CMOS Serial  
Data I/O. In LVDS I/O mode, these pins are Hi-Z.  
+
SDI /SDI (Pins26/27):LVDSPositiveandNegativeSerial  
+
Data Input. Differentially drive SDI /SDI with the desired  
24-bitSoftSpanconfigurationword(seeTable1a),latched  
+
on both the rising and falling edges of SCKI /SCKI . The  
unconnected. Logic levels are determined by OV .  
+
DD  
SDI /SDI input pair is internally terminated with a 100Ω  
SCKI (Pin 29): CMOS Serial Clock Input. Drive SCKI with  
the serial I/O clock. SCKI rising edges latch serial data in  
on SDI and clock serial data out on SDO0 to SDO7. For  
standard SPI bus operation, capture output data at the  
receiver on rising edges of SCKI. SCKI is allowed to idle  
differential resistor when CS is low.  
+
SCKI /SCKI (Pins 28/29): LVDS Positive and Negative  
+
Serial Clock Input. Differentially drive SCKI /SCKI with  
+
the serial I/O clock. SCKI /SCKI rising and falling edges  
+
latch serial data in on SDI /SDI and clock serial data out  
either high or low. Logic levels are determined by OV .  
+
+
DD  
on SDO /SDO . Idle SCKI /SCKI low, including when  
+
OV (Pin 31): I/O Interface Power Supply. In CMOS I/O  
transitioning CS. The SCKI /SCKI input pair is internally  
terminatedwitha100ΩdifferentialresistorwhenCSislow.  
DD  
mode, the range of OV is 1.71V to 5.25V. Bypass OV  
DD  
DD  
to GND (Pin 30) close to the pin with a 0.1μF ceramic  
OV (Pin 31): I/O Interface Power Supply. In LVDS I/O  
DD  
capacitor.  
mode, therangeofOV is2.375Vto5.25V. BypassOV  
DD  
DD  
SCKO (Pin 32): CMOS Serial Clock Output. SCKI rising  
edges trigger transitions on SCKO that are skew-matched  
to the serial output data streams on SDO0 to SDO7. The  
resulting SCKO frequency is half that of SCKI. Rising and  
falling edges of SCKO may be used to capture SDO data  
at the receiver (FPGA) in double data rate (DDR) fashion.  
For standard SPI bus operation, SCKO is not used and  
should be left unconnected. SCKO is forced low at the  
to GND (Pin 30) close to the pin with a 0.1μF ceramic  
capacitor.  
+
SCKO /SCKO (Pins 32/33): LVDS Positive and Negative  
+
Serial Clock Output. SCKO /SCKO outputs a copy of the  
+
input serial I/O clock received on SCKI /SCKI , skew-  
+
matchedwiththeserialoutputdatastreamonSDO /SDO .  
+
Use the rising and falling edges of SCKO /SCKO to cap-  
+
+
ture SDO /SDO data at the receiver (FPGA). The SCKO /  
fallingedgeofBUSY. LogiclevelsaredeterminedbyOV .  
DD  
SCKO output pair must be differentially terminated with  
SDI (Pin 37): CMOS Serial Data Input. Drive this pin with  
the desired 24-bit SoftSpan configuration word (see Table  
1a), latched on the rising edges of SCKI. If all channels  
will be configured to operate only in SoftSpan 7, tie SDI  
to OV . Logic levels are determined by OV .  
a 100Ω resistor at the receiver (FPGA).  
+
SDO /SDO (Pins 34/35): LVDS Positive and Negative  
Serial Data Output. The most recent conversion result  
along with channel configuration information is clocked  
+
DD  
DD  
out onto SDO /SDO on both rising and falling edges of  
+
+
CS (Pin 39): Chip Select Input. The serial data I/O bus is  
enabled when CS is low and is disabled and Hi-Z when  
CS is high. CS also gates the external shift clock, SCKI.  
SCKI /SCKI , beginning with channel 0. The SDO /SDO  
output pair must be differentially terminated with a 100Ω  
resistor at the receiver (FPGA).  
Logic levels are determined by OV .  
DD  
CS (Pin 39): Chip Select Input. The serial data I/O bus is  
enabled when CS is low, and is disabled and Hi-Z when  
+
CS is high. CS also gates the external shift clock, SCKI /  
SCKI .Theinternal100Ωdifferentialterminationresistors  
+
+
ontheSCKI /SCKI andSDI /SDI inputpairsaredisabled  
when CS is high. Logic levels are determined by OV .  
DD  
Rev A  
14  
For more information www.analog.com  
LTC2358-16  
CONFIGURATION TABLES  
Table 1a. SoftSpan Configuration Table. Use This Table with Table 1b to Choose Independent Binary SoftSpan Codes SS[2:0] for Each  
Channel Based on Desired Analog Input Range. Combine SoftSpan Codes to Form 24-Bit SoftSpan Configuration Word S[23:0]. Use  
Serial Interface to Write SoftSpan Configuration Word to LTC2358-16, as shown in Figure 18  
BINARY SoftSpan CODE  
SS[2:0]  
BINARY FORMAT OF  
CONVERSION RESULT  
ANALOG INPUT RANGE  
2.5 • V  
FULL SCALE RANGE  
5 • V  
111  
110  
101  
100  
011  
010  
001  
000  
Two’s Complement  
Two’s Complement  
Straight Binary  
Straight Binary  
Two’s Complement  
Two’s Complement  
Straight Binary  
All Zeros  
REFBUF  
REFBUF  
2.5 • V /1.024  
REFBUF  
5 • V  
/1.024  
REFBUF  
0V to 2.5 • V  
2.5 • V  
REFBUF  
REFBUF  
0V to 2.5 • V /1.024  
REFBUF  
2.5 • V  
/1.024  
REFBUF  
1.25 • V  
2.5 • V  
REFBUF  
REFBUF  
1.25 • V /1.024  
REFBUF  
2.5 • V  
/1.024  
REFBUF  
0V to 1.25 • V  
1.25 • V  
REFBUF  
Channel Disabled  
REFBUF  
Channel Disabled  
Table 1b. Reference Configuration Table. The LTC2358-16 Supports Three Reference Configurations. Analog Input Range Scales with  
the Converter Master Reference Voltage, VREFBUF  
BINARY SoftSpan CODE  
REFERENCE CONFIGURATION  
V
REFIN  
V
ANALOG INPUT RANGE  
REFBUF  
SS[2:0]  
111  
110  
101  
100  
011  
010  
001  
111  
110  
101  
100  
011  
010  
001  
111  
110  
101  
100  
011  
010  
001  
10.24V  
10V  
0V to 10.24V  
0V to 10V  
5.12V  
Internal Reference with  
Internal Buffer  
2.048V  
4.096V  
5V  
0V to 5.12V  
6.25V  
6.104V  
0V to 6.25V  
0V to 6.104V  
3.125V  
1.25V  
(Min Value)  
2.5V  
3.052V  
External Reference with  
Internal Buffer  
0V to 3.125V  
11V  
(REFIN Pin Externally  
Overdriven)  
10.742V  
0V to 11V  
0V to 10.742V  
5.5V  
2.2V  
(Max Value)  
4.4V  
5.371V  
0V to 5.5V  
Rev A  
15  
For more information www.analog.com  
LTC2358-16  
CONFIGURATION TABLES  
Table 1b. Reference Configuration Table (Continued). The LTC2358-16 Supports Three Reference Configurations. Analog Input Range  
Scales with the Converter Master Reference Voltage, VREFBUF  
BINARY SoftSpan CODE  
REFERENCE CONFIGURATION  
V
REFIN  
V
ANALOG INPUT RANGE  
REFBUF  
SS[2:0]  
111  
110  
101  
100  
011  
010  
001  
111  
110  
101  
100  
011  
010  
001  
6.25V  
6.104V  
0V to 6.25V  
0V to 6.104V  
3.125V  
2.5V  
0V  
(Min Value)  
External Reference  
Unbuffered  
3.052V  
0V to 3.125V  
12.5V  
(REFBUF Pin  
Externally Overdriven,  
REFIN Pin Grounded)  
12.207V  
0V to 12.5V  
0V to 12.207V  
6.25V  
5V  
0V  
(Max Value)  
6.104V  
0V to 6.25V  
Rev A  
16  
For more information www.analog.com  
LTC2358-16  
FUNCTIONAL BLOCK DIAGRAM  
CMOS I/O Mode  
ꢋꢌꢖꢖꢓRꢀ  
ꢅꢅ  
ꢂꢜ  
ꢁꢁ  
ꢁꢁ  
ꢁꢁꢔꢋꢍꢝ  
LTC2358-16  
ꢇꢈꢃ  
ꢀꢕꢠ  
ꢀꢕꢠ  
ꢀꢕꢠ  
ꢀꢕꢠ  
ꢀꢕꢠ  
ꢀꢕꢠ  
ꢀꢕꢠ  
ꢀꢕꢠ  
ꢇꢈꢃ  
ꢗꢞꢙꢜ  
RꢓꢛꢌꢔAꢑꢂR  
ꢀꢁꢂꢃ  
ꢇꢈꢎ  
ꢇꢈꢎ  
ꢇꢈꢗ  
ꢀꢁꢂꢄ  
ꢀꢅꢆꢂ  
ꢀꢁꢇ  
ꢅꢒꢂꢀ  
ꢀꢓRꢇAꢔ  
ꢇꢕꢂ  
ꢇꢈꢗ  
ꢎꢏꢐꢋꢇꢑ  
ꢀAR Aꢁꢅ  
ꢎꢏ ꢋꢇꢑꢀ  
ꢇꢈꢘ  
ꢇꢈꢑꢓRꢖAꢅꢓ  
ꢇꢈꢘ  
ꢀꢅꢆꢇ  
CS  
ꢇꢈꢟ  
ꢇꢈꢟ  
ꢇꢈꢙ  
ꢇꢈꢙ  
ꢇꢈꢏ  
RꢓꢖꢓRꢓꢈꢅꢓ  
ꢋꢌꢖꢖꢓR  
ꢇꢈꢏ  
ꢗꢃꢢ  
ꢋꢌꢀꢍ  
ꢅꢂꢈꢑRꢂꢔ  
ꢔꢂꢛꢇꢅ  
ꢗꢞꢃꢟꢚꢜ  
RꢓꢖꢓRꢓꢈꢅꢓ  
ꢇꢈꢄ  
×  
ꢇꢈꢄ  
ꢛꢈꢁ  
Rꢓꢖꢇꢈ  
Rꢓꢖꢋꢌꢖ  
ꢅꢈꢜ ꢝꢁ ꢁꢀꢕCMOS  
ꢓꢓ  
ꢗꢘꢙꢚꢎꢏ ꢋꢁꢃꢎ  
LVDS I/O Mode  
ꢅꢅ  
ꢂꢒ  
ꢁꢁ  
ꢊꢋꢕꢕꢓRꢀ  
ꢁꢁ  
ꢁꢁꢑꢊꢌꢛ  
LTC2358-16  
ꢇꢈꢉ  
ꢀꢔꢞ  
ꢇꢈꢉ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢅꢆꢂ  
ꢀꢅꢆꢂ  
ꢀꢁꢇ  
ꢖꢜꢘꢒ  
RꢓꢚꢋꢑAꢐꢂR  
ꢇꢈꢍ  
ꢀꢔꢞ  
ꢀꢔꢞ  
ꢀꢔꢞ  
ꢀꢔꢞ  
ꢀꢔꢞ  
ꢀꢔꢞ  
ꢀꢔꢞ  
ꢇꢈꢍ  
ꢇꢈꢖ  
ꢁꢀ  
ꢀꢓRꢇAꢑ  
ꢇꢔꢂ  
ꢇꢈꢖ  
ꢍꢎꢏꢊꢇꢐ  
ꢍꢎ ꢊꢇꢐꢀ  
ꢀAR Aꢁꢅ  
ꢇꢈꢗ  
ꢀꢁꢇ  
ꢇꢈꢐꢓRꢕAꢅꢓ  
ꢇꢈꢗ  
ꢀꢅꢆꢇ  
ꢀꢅꢆꢇ  
ꢇꢈꢝ  
ꢇꢈꢝ  
CS  
ꢇꢈꢘ  
ꢇꢈꢘ  
ꢇꢈꢎ  
RꢓꢕꢓRꢓꢈꢅꢓ  
ꢊꢋꢕꢕꢓR  
ꢇꢈꢎ  
ꢖꢉꢢ  
ꢊꢋꢀꢌ  
ꢅꢂꢈꢐRꢂꢑ  
ꢑꢂꢚꢇꢅ  
ꢖꢜꢉꢝꢙꢒ  
RꢓꢕꢓRꢓꢈꢅꢓ  
ꢇꢈꢟ  
×  
ꢇꢈꢟ  
ꢚꢈꢁ  
Rꢓꢕꢇꢈ  
Rꢓꢕꢊꢋꢕ  
ꢅꢈꢒ ꢛꢁ ꢁꢀꢔCMOS  
ꢓꢓ  
ꢖꢗꢘꢙꢍꢎ ꢊꢁꢉꢖ  
Rev A  
17  
For more information www.analog.com  
LTC2358-16  
TIMING DIAGRAM  
CMOS I/O Mode  
CS ꢏ ꢐꢋ ꢏ ꢊ  
ꢀAꢛꢐꢜꢒ ꢍ  
ꢌꢍꢎ  
ꢀAꢛꢐꢜꢒ ꢍ ꢝ ꢃ  
ꢘꢖꢀꢙ  
ꢀꢌꢚꢗ  
ꢀꢋꢗ  
ꢌꢑꢍꢎꢒRꢓ  
AꢌꢕꢖꢗRꢒ  
ꢉ ꢃꢊ ꢃꢃ ꢃꢁ ꢃꢂ ꢃꢄ ꢃꢅ ꢃꢆ ꢃꢇ ꢃꢈ ꢃꢉ ꢁꢊ ꢁꢃ ꢁꢁ ꢁꢂ ꢁꢄ  
ꢋꢑꢍARꢒ  
ꢀꢁꢂ ꢁꢁ ꢀꢁꢃ ꢀꢁꢊ ꢀꢃꢉ ꢀꢃꢈ ꢀꢃꢇ ꢀꢃꢆ ꢀꢃꢅ ꢀꢃꢄ ꢀꢃꢂ ꢀꢃꢁ ꢀꢃꢃ ꢀꢃꢊ  ꢀꢈ ꢀꢇ ꢀꢆ ꢀꢅ ꢀꢄ ꢀꢂ ꢀꢁ ꢀꢃ ꢀꢊ  
ꢀꢞꢟꢠꢀꢡꢢꢣ ꢌꢑꢍꢤꢗꢥꢖRAꢓꢗꢑꢍ ꢦꢑRꢋ ꢤꢑR ꢌꢑꢍꢎꢒRꢀꢗꢑꢍ ꢍ ꢝ ꢃ  
ꢀꢌꢚꢑ  
ꢀꢋꢑꢊ  
ꢋꢑꢍARꢒ  
ꢋꢑꢍARꢒ  
ꢋꢃꢅ ꢃꢄ ꢋꢃꢂ ꢋꢃꢁ ꢋꢃꢃ ꢋꢃꢊ ꢋꢉ ꢋꢈ ꢇ ꢋꢆ ꢋꢅ ꢋꢄ ꢋꢂ ꢋꢁ ꢋꢃ ꢋꢊ  
ꢌꢑꢍꢎꢒRꢀꢗꢑꢍ Rꢒꢀꢖꢓ  
ꢌꢁ ꢌꢃ ꢌꢊ ꢀꢁ ꢀꢀꢃ ꢀꢀꢊ ꢋꢃꢅ  
ꢌꢧAꢍꢍꢒꢜ ꢗꢋ ꢀꢞꢟꢠꢀꢡꢢꢣ  
ꢌꢑꢍꢎꢒRꢀꢗꢑꢍ Rꢒꢀꢖꢓ  
ꢌꢧAꢍꢍꢒꢜ ꢊ  
ꢌꢑꢍꢎꢒRꢀꢗꢑꢍ ꢍ  
ꢌꢧAꢍꢍꢒꢜ ꢃ  
ꢌꢑꢍꢎꢒRꢀꢗꢑꢍ ꢍ  
ꢀꢋꢑꢇ  
ꢋꢃꢅ ꢃꢄ ꢋꢃꢂ ꢋꢃꢁ ꢋꢃꢃ ꢋꢃꢊ ꢋꢉ ꢋꢈ ꢇ ꢋꢆ ꢋꢅ ꢋꢄ ꢋꢂ ꢋꢁ ꢋꢃ ꢋꢊ  
ꢌꢑꢍꢎꢒRꢀꢗꢑꢍ Rꢒꢀꢖꢓ  
ꢌꢁ ꢌꢃ ꢌꢊ ꢀꢁ ꢀꢀꢃ ꢀꢀꢊ ꢋꢃꢅ  
ꢌꢧAꢍꢍꢒꢜ ꢗꢋ ꢀꢞꢟꢠꢀꢡꢢꢣ  
ꢌꢑꢍꢎꢒRꢀꢗꢑꢍ Rꢒꢀꢖꢓ  
ꢌꢧAꢍꢍꢒꢜ ꢇ  
ꢌꢑꢍꢎꢒRꢀꢗꢑꢍ ꢍ  
ꢌꢧAꢍꢍꢒꢜ ꢊ  
ꢌꢑꢍꢎꢒRꢀꢗꢑꢍ ꢍ  
ꢁꢂꢅꢈꢃꢆ ꢓꢋꢊꢃ  
LVDS I/O Mode  
CS ꢓ ꢔꢋ ꢓ ꢊ  
ꢀAꢐꢔꢞꢖ  
ꢍ ꢟ ꢃ  
ꢀAꢐꢔꢞꢖ ꢍ  
ꢌꢍꢎ  
ꢏꢌꢐꢑꢀꢒ  
• • •  
• • •  
ꢛꢙꢀꢜ  
AꢌꢘꢙꢚRꢖ  
ꢏꢌꢐꢑꢀꢒ  
ꢌꢑꢍꢎꢖRꢕ  
ꢃꢊ ꢃꢃ ꢃꢁ ꢃꢂ ꢃꢄ ꢃꢅ ꢃꢆ ꢃꢇ ꢃꢈ ꢃꢉ ꢁꢊ ꢁꢃ ꢁꢁ ꢁꢂ ꢁꢄ ꢁꢅ ꢁꢆ  
ꢃꢈꢆ ꢃꢈꢇ ꢃꢈꢈ ꢃꢈꢉ ꢃꢉꢊ ꢃꢉꢃ ꢃꢉꢁ  
ꢀꢌꢝꢚ  
ꢋꢀꢒ  
• • •  
• • •  
ꢀꢋꢚ  
ꢋꢀꢒ  
ꢋꢑꢍARꢖ  
ꢀꢁꢂ ꢁꢁ ꢀꢁꢃ ꢀꢁꢊ ꢀꢃꢉ ꢀꢃꢈ ꢀꢃꢇ ꢀꢃꢆ ꢀꢃꢅ ꢀꢃꢄ ꢀꢃꢂ ꢀꢃꢁ ꢀꢃꢃ ꢀꢃꢊ  ꢀꢈ ꢀꢇ ꢀꢆ ꢀꢅ ꢀꢄ ꢀꢂ ꢀꢁ ꢀꢃ ꢀꢊ  
ꢀꢠꢡꢢꢀꢣꢤꢥ ꢌꢑꢍꢦꢚꢧꢙRAꢕꢚꢑꢍ ꢨꢑRꢋ ꢦꢑR ꢌꢑꢍꢎꢖRꢀꢚꢑꢍ ꢍ ꢟ ꢃ  
ꢀꢌꢝꢑ  
ꢋꢀꢒ  
• • •  
ꢀꢋꢑ  
ꢋꢀꢒ  
ꢋꢑꢍARꢖ ꢋꢃꢅ ꢃꢄ ꢋꢃꢂ ꢋꢃꢁ ꢋꢃꢃ ꢋꢃꢊ ꢋꢉ ꢋꢈ ꢇ ꢋꢆ ꢋꢅ ꢋꢄ ꢋꢂ ꢋꢁ ꢋꢃ ꢋꢊ  
ꢌꢑꢍꢎꢖRꢀꢚꢑꢍ Rꢖꢀꢙꢕ  
ꢌꢁ ꢌꢃ ꢌꢊ ꢀꢁ ꢀꢀꢃ ꢀꢀꢊ ꢋꢃꢅ ꢋꢃꢄ ꢋꢃꢂ • • • ꢊ ꢌꢁ ꢌꢃ ꢌꢊ ꢀꢁ ꢀꢀꢃ ꢀꢀꢊ ꢋꢃꢅ  
ꢌꢑꢍꢎꢖRꢀꢚꢑꢍ  
Rꢖꢀꢙꢕ  
ꢌꢩAꢍꢍꢖꢞ ꢚꢋ ꢀꢠꢡꢢꢀꢣꢤꢥ  
ꢌꢩAꢍꢍꢖꢞ ꢚꢋ ꢀꢠꢡꢢꢀꢣꢤꢥ  
ꢌꢩAꢍꢍꢖꢞ ꢊ  
ꢌꢑꢍꢎꢖRꢀꢚꢑꢍ ꢍ  
ꢌꢩAꢍꢍꢖꢞ ꢃ  
ꢌꢑꢍꢎꢖRꢀꢚꢑꢍ ꢍ  
ꢌꢩAꢍꢍꢖꢞ ꢇ  
ꢌꢑꢍꢎꢖRꢀꢚꢑꢍ ꢍ  
ꢌꢩAꢍꢍꢖꢞ ꢊ  
ꢌꢑꢍꢎꢖRꢀꢚꢑꢍ ꢍ  
ꢁꢂꢅꢈꢃꢆ ꢕꢋꢊꢁ  
Rev A  
18  
For more information www.analog.com  
LTC2358-16  
APPLICATIONS INFORMATION  
OVERVIEW  
CONVERTER OPERATION  
The LTC2358-16 is a 16-bit, low noise 8-channel simul-  
taneous sampling successive approximation register  
(SAR) ADC with buffered differential, wide common  
mode range picoamp inputs. The ADC operates from a  
5V low voltage supply and flexible high voltage supplies,  
nominally 15V. Using the integrated low-drift reference  
The LTC2358-16 operates in two phases. During the ac-  
quisitionphase, thesamplingcapacitorsineachchannel’s  
sample-and-hold (S/H) circuit connect to their respective  
analog input buffers, which track the differential analog  
input voltage (V + – V –). A rising edge on the CNV pin  
IN  
IN  
transitions all channels’ S/H circuits from track mode to  
hold mode, simultaneously sampling the input signals  
on all channels and initiating a conversion. During the  
conversion phase, each channel’s sampling capacitors  
are connected, one channel at a time, to a 16-bit charge  
redistribution capacitor D/A converter (CDAC). The CDAC  
is sequenced through a successive approximation algo-  
rithm, effectively comparing the sampled input voltage  
with binary-weighted fractions of the channel’s SoftSpan  
and buffer (V  
= 4.096V nominal), each channel of  
REFBUF  
this SoftSpan ADC can be independently configured on a  
conversion-by-conversion basis to accept 10.24V, 0V to  
10.24V, 5.12V, or 0V to 5.12V signals. The input signal  
range may be expanded up to 12.5V using an external  
5V reference. Individual channels may also be disabled to  
increase throughput on the remaining channels.  
The integrated picoamp-input analog buffers, wide input  
common mode range, and 128dB CMRR of the LTC2358-  
16 allow the ADC to directly digitize a variety of signals  
using minimal board space and power. This input signal  
flexibility, combined with 1LSB INL, no missing codes  
at 16 bits, and 94.2dB SNR, makes the LTC2358-16 an  
ideal choice for many high voltage applications requiring  
wide dynamic range.  
full-scale range (e.g., V /2, V /4 … V /65536) us-  
FSR  
FSR  
FSR  
ing a differential comparator. At the end of this process,  
the CDAC output approximates the channel’s sampled  
analog input. Once all channels have been converted in  
this manner, the ADC control logic prepares the 16-bit  
digital output codes from each channel for serial transfer.  
TRANSFER FUNCTION  
The absolute common mode input range (V + 4V to  
EE  
TheLTC2358-16digitizeseachchannel’sfull-scalevoltage  
V
– 4V) is determined by the choice of high voltage  
CC  
16  
range into 2 levels. In conjunction with the ADC master  
supplies. These supplies may be biased asymmetrically  
reference voltage, V  
, a channel’s SoftSpan configu-  
REFBUF  
around ground and include the ability for V to be tied  
EE  
ration determines its input voltage range, full-scale range,  
LSB size, and the binary format of its conversion result, as  
shown in Tables 1a and 1b. For example, employing the  
directly to ground.  
TheLTC2358-16supportspin-selectableSPICMOS(1.8V  
to 5V) and LVDS serial interfaces, enabling it to com-  
municate equally well with legacy microcontrollers and  
modern FPGAs. In CMOS mode, applications may employ  
betweenoneandeightlanesofserialoutputdata, allowing  
the user to optimize bus width and data throughput. The  
LTC2358-16typicallydissipates219mWwhenconverting  
eight channels simultaneously at 200ksps per channel.  
Optional nap and power down modes may be employed to  
furtherreducepowerconsumptionduringinactiveperiods.  
internal reference and buffer (V  
= 4.096V nominal),  
REFBUF  
SoftSpan 7 configures a channel to accept a 10.24V bi-  
polar analog input voltage range, which corresponds to a  
20.48Vfull-scalerangewitha312.5μVLSB.OtherSoftSpan  
configurationsandreferencevoltagesmaybeemployedto  
convert both larger and smaller bipolar and unipolar input  
ranges. Conversion results are output in two’s comple-  
ment binary format for all bipolar SoftSpan ranges, and  
in straight binary format for all unipolar SoftSpan ranges.  
Rev A  
19  
For more information www.analog.com  
LTC2358-16  
APPLICATIONS INFORMATION  
The ideal two’s complement transfer function is shown in  
Figure 2, while the ideal straight binary transfer function  
is shown in Figure 3.  
LTC2358-16 enables it to accept a wide variety of signal  
swings,includingtraditionalclassesofanaloginputsignals  
such as pseudo-differential unipolar, pseudo-differential  
true bipolar, and fully differential, simplifying signal chain  
design. For conversion of signals extending to V , the  
EE  
011...111  
unbuffered LTC2348-16 ADC is recommended.  
BIPOLAR  
ZERO  
011...110  
The wide operating range of the high voltage supplies  
offers further input common mode flexibility. As long as  
000...001  
000...000  
111...111  
111...110  
the voltage difference limits of 10V ≤ (V – V ) ≤ 38V  
CC  
EE  
are observed, V and V may be independently biased  
CC  
EE  
anywhere within their own individually allowed operating  
ranges, including the ability for V to be tied directly to  
EE  
100...001  
100...000  
FSR = +FS – –FS  
1LSB = FSR/65536  
ground. This feature enables the common mode input  
range of the LTC2358-16 to be tailored to specific ap-  
plication requirements.  
–1 0V  
1
–FSR/2  
FSR/2 – 1LSB  
LSB  
LSB  
INPUT VOLTAGE (V)  
235816 F02  
In all SoftSpan ranges, each channel’s analog inputs can  
be modeled by the equivalent circuit shown in Figure 4. At  
Figure 2. LTC2358-16 Two’s Complement Transfer Function  
the start of acquisition, the sampling capacitors (C  
)
SAMP  
+
connecttotheintegratedbuffersBuffer /Buffer through  
the sampling switches. The sampled voltage is reset dur-  
ing the conversion process and is therefore re-acquired  
for each new conversion.  
111...111  
111...110  
100...001  
100...000  
The diodes between the inputs and the V and V sup-  
CC  
EE  
UNIPOLAR  
011...111  
pliesprovideinputESDprotection.Whilewithinthesupply  
voltages, the analog inputs of the LTC2358-16 draw only  
5pA typical DC leakage current and the ESD protection  
diodes don’t turn on. This offers a significant advantage  
over external op amp buffers, which often have diode  
protection that turns on during transients and corrupts  
the voltage on any filter capacitors at their inputs.  
ZERO  
011...110  
000...001  
FSR = +FS  
1LSB = FSR/65536  
000...000  
0V  
FSR – 1LSB  
INPUT VOLTAGE (V)  
235816 F03  
Figure 3. LTC2358-16 Straight Binary Transfer Function  
V
CC  
C
SAMP  
+
BUFFER  
R
SAMP  
750Ω  
30pF  
+
BUFFERED ANALOG INPUTS  
IN  
Each channel of the LTC2358-16 simultaneously samples  
V
EE  
BIAS  
the voltage difference (V + – V –) between its analog  
IN  
IN  
VOLTAGE  
V
CC  
C
SAMP  
30pF  
input pins over a wide common mode input range while  
attenuating unwanted signals common to both input pins  
by the common-mode rejection ratio (CMRR) of the ADC.  
WidecommonmodeinputrangecoupledwithhighCMRR  
BUFFER  
R
SAMP  
750Ω  
235816 F04  
IN  
V
EE  
+
allows the IN /IN analog inputs to swing with an arbitrary  
relationship to each other, provided each pin remains  
Figure 4. Equivalent Circuit for Differential Analog  
Inputs, Single Channel Shown  
between (V + 4V) and (V – 4V). This feature of the  
EE  
CC  
Rev A  
20  
For more information www.analog.com  
LTC2358-16  
APPLICATIONS INFORMATION  
Bipolar SoftSpan Input Ranges  
less than 10kΩ of impedance can drive the passive 3pF  
analog input capacitance directly. For higher impedances  
and slow-settling circuits, add a 680pF capacitor at the  
pins to maintain the full DC accuracy of the LTC2358-16.  
For channels configured in SoftSpan ranges 7, 6, 3,  
or 2, the LTC2358-16 digitizes the differential analog  
input voltage (V + – V –) over a bipolar span of  
IN  
IN  
REFBUF  
2.5 • V  
, 2.5 • V  
/1.024, 1.25 • V , or  
The very high input impedance of the unity gain buffers in  
the LTC2358-16 greatly reduces the drive requirements of  
the differential amplifier and make it possible to include  
optional RC filters with kΩ impedance and arbitrarily slow  
time constants for anti-aliasing or other purposes. Micro-  
power op amps with limited drive capability are also well  
suited to drive the high impedance analog inputs directly.  
REFBUF  
REFBUF  
1.25 • V  
/1.024, respectively, as shown in Table 1a.  
REFBUF  
TheseSoftSpanrangesareusefulfordigitizinginputsignals  
+
where IN and IN swing above and below each other.  
Traditionalexamplesincludefullydifferentialinputsignals,  
+
where IN and IN are driven 180 degrees out-of-phase  
with respect to each other centered around a common  
mode voltage (V + + V –)/2, and pseudo-differential  
IN  
IN  
The LTC2358-16 features proprietary circuitry to achieve  
exceptional internal crosstalk isolation between channels  
(109dB typical). The PC board wiring to the analog inputs  
shouldbeshortandshieldedtopreventexternalcapacitive  
crosstalkbetweenchannels.Thecapacitancebetweenadja-  
centpackagepinsis0.16pF.Lowsourceresistanceand/or  
high source capacitance help reduce external capacitively  
coupled crosstalk. Single ended input drive also enjoys  
additionalexternalcrosstalkisolationbecauseeveryother  
input pin is grounded, or at a low impedance DC source,  
and serves as a shield between channels.  
+
true bipolar input signals, where IN swings above and  
below a ground reference level, driven on IN . Regardless  
of the chosen SoftSpan range, the wide common mode  
+
input range and high CMRR of the IN /IN analog inputs  
allow them to swing with an arbitrary relationship to each  
other, provided each pin remains between (V – 4V) and  
CC  
(V + 4V). The output data format for all bipolar SoftSpan  
EE  
ranges is two’s complement.  
Unipolar SoftSpan Input Ranges  
For channels configured in SoftSpan ranges 5, 4, or 1, the  
LTC2358-16 digitizes the differential analog input voltage  
INPUT OVERDRIVE TOLERANCE  
(V + – V –) over a unipolar span of 0V to 2.5 • V ,  
IN  
IN  
REFBUF  
, respec-  
DrivingananaloginputaboveV onanychannelupto10mA  
0V to 2.5 • V  
/1.024, or 0V to 1.25 • V  
CC  
REFBUF  
REFBUF  
willnotaffectconversionresultsonotherchannels.Approx-  
tively, as shown in Table 1a. These SoftSpan ranges are  
+
imately70%ofthisoverdrivecurrentwillflowoutoftheV  
usefulfordigitizinginputsignalswhereIN remainsabove  
CC  
pinandtheremaining30%willflowoutofV .Thiscurrent  
IN . A traditional example includes pseudo-differential  
EE  
+
flowing out of V will produce heat across the V – V  
unipolar input signals, where IN swings above a ground  
EE  
CC  
EE  
voltage drop and must be taken into account for the total  
reference level, driven on IN . Regardless of the chosen  
Absolute Maximum power dissipation of 500mW. Driving  
SoftSpan range, the wide common mode input range and  
+
an analog input below V may corrupt conversion results  
high CMRR of the IN /IN analog inputs allow them to  
swingwithanarbitraryrelationshiptoeachother,provided  
each pin remains between (V – 4V) and (V + 4V).  
EE  
on other channels. This product can handle input currents  
of up to 100mA below V or above V without latchup.  
EE  
CC  
CC  
EE  
The output data format for all unipolar SoftSpan ranges  
is straight binary.  
Keep in mind that driving the inputs above V or below  
CC  
V may reverse the normal current flow from the external  
EE  
power supplies driving these pins.  
INPUT DRIVE CIRCUITS  
The CMOS buffer input stage offers a very high degree of  
transient isolation from the sampling process. Most sen-  
sors,signalconditioningamplifiersandfilternetworkswith  
Rev A  
21  
For more information www.analog.com  
LTC2358-16  
APPLICATIONS INFORMATION  
Input Filtering  
feature of the LTC2358-16 enables it to accept a wide  
variety of signal swings, simplifying signal chain design.  
The true high impedance analog inputs can accommodate  
a very wide range of passive or active signal conditioning  
filters. The buffered ADC inputs have an analog bandwidth  
of6MHz,andimposenoparticularbandwidthrequirement  
onexternalfilters.Theexternalinputfilterscanthereforebe  
optimized independent of the ADC to reduce signal chain  
noise and interference. A common filter configuration is  
thesimpleanti-aliasingandnoisereducingRCfilterwithits  
pole at half the sampling frequency. For example, 100kHz  
with R=2.43kΩ and C=680pF as shown in Figure 5.  
The two-tone test shown in Figure 6b demonstrates the  
arbitraryinputdrivecapabilityoftheLTC2358-16.Thistest  
+
simultaneouslydrivesIN witha7dBFS2kHzsingle-ended  
sinewaveandIN witha7dBFS3.1kHzsingle-endedsine  
wave. Together, these signals sweep the analog inputs  
across a wide range of common mode and differential  
mode voltage combinations, similar to the more general  
arbitrary input signal case. They also have a simple spec-  
tral representation. An ideal differential converter with no  
common-mode sensitivity will digitize this signal as two  
−7dBFS spectral tones, one at each sine wave frequency.  
The FFT plot in Figure 6b demonstrates the LTC2358-16  
response approaches this ideal, with 119dB of SFDR  
limited by the converter's second harmonic distortion  
ꢁꢂꢃ  
ꢎꢘꢅꢕꢎꢏAꢄ  
ꢅRꢖꢒ ꢗꢕꢘꢎꢄAR  
ꢙꢁꢍꢃ  
ꢄꢎꢔꢘAꢓꢓ ꢌꢕꢒR  
R ꢟ ꢇꢚꢜꢈꢠ  
ꢍꢚꢁꢛꢌ  
ꢕꢏ  
ꢍꢃ  
ꢀꢁꢍꢃ  
ꢆꢆ  
ꢕꢏꢍ  
ꢕꢏꢍ  
ꢋꢉꢍꢞꢌ  
ꢖꢏꢕꢘꢎꢄAR  
ꢙꢁꢍꢃ  
response to the 3.1kHz sine wave on IN .  
ꢆꢇꢈꢂꢉꢊꢁꢋ  
ꢕꢏ  
ꢍꢃ  
The ability of the LTC2358-16 to accept arbitrary signal  
swings over a wide input common mode range with high  
CMRR can simplify application solutions. In practice,  
many sensors produce a differential sensor voltage riding  
on top of a large common mode signal. Figure 7a depicts  
one way of using the LTC2358-16 to digitize signals of  
this type. The amplifier stage provides a differential gain  
of approximately 10V/V to the desired sensor signal while  
the unwanted common mode signal is attenuated by the  
ADCCMRR.Thecircuitemploysthe 5VSoftSpanrangeof  
the ADC. Figure 7b shows measured CMRR performance  
of this solution, which is competitive with the best com-  
mercially available instrumentation amplifiers. Figure 7c  
shows measured AC performance of this solution.  
Rꢒꢌꢗꢖꢌ  
ꢜꢝꢛꢌ  
Rꢒꢌꢕꢏ  
ꢒꢒ  
ꢀꢁꢍꢃ  
ꢍꢚꢁꢛꢌ  
ꢍꢚꢁꢛꢌ  
ꢀꢁꢂꢃ  
ꢎꢏꢑAꢏꢏꢒꢄ ꢍ ꢓꢑꢎꢔꢏ ꢌꢎR ꢆꢄARꢕꢅꢐ  
ꢇꢈꢂꢉꢁꢋ ꢌꢍꢂ  
Figure 5. Filtering Single-Ended Input Signals  
High quality capacitors and resistors should be used in  
the RC filters since these components can add distortion.  
NPO/COG and silver mica type dielectric capacitors have  
excellent linearity. Carbon surface mount resistors can  
generate distortion from self-heating and from damage  
thatmayoccurduringsoldering. Metalfilmsurfacemount  
resistors are much less susceptible to both problems.  
In Figure 8, another application circuit is shown which  
uses two channels of the LTC2358-16 to simultaneously  
sensethevoltageandbidirectionalcurrentthroughasense  
resistor over a wide common mode range.  
Arbitrary and Fully Differential Analog Input Signals  
The wide common mode input range and high CMRR of  
+
the LTC2358-16 allow each channel’s IN and IN pins to  
swingwithanarbitraryrelationshiptoeachother,provided  
each pin remains between (V – 4V) and (V + 4V). This  
CC  
EE  
Rev A  
22  
For more information www.analog.com  
LTC2358-16  
APPLICATIONS INFORMATION  
AR RAR  
R
A
AR  
R
AR  
R
R
A
R
AR  
Figure 6a. Input Arbitrary, Fully Differential, True Bipolar, and Unipolar Signals  
Arbitrary Drive  
Fully Differential Drive  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂꢃꢄꢅꢆ RAꢇꢈ  
ꢀꢁꢂR ꢃ ꢄꢄꢅꢆꢇ  
ꢀꢁR ꢂ ꢃꢄꢅꢆꢇꢈ  
ꢀꢁꢂꢃꢄꢅꢆ RAꢇꢈ  
ꢀꢁR ꢂ ꢃꢄꢅꢆꢇꢈ  
ꢀꢁꢂ ꢃ ꢄꢅꢅꢆꢇꢈ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂAꢃ ꢄ ꢅꢆꢇꢈꢉꢊ  
ꢀꢁꢂR ꢃ ꢄꢅꢆꢇꢈ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂꢂ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢂ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃꢄꢅ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁꢁ  
ꢀRꢁꢂꢃꢁꢄꢅꢆ ꢇꢈꢉꢊꢋ  
ꢀRꢁꢂꢃꢁꢄꢅꢆ ꢇꢈꢉꢊꢋ  
ꢀꢁꢂꢃꢄꢅ ꢆꢇꢅꢈ  
ꢀꢁꢂꢃꢄꢅ ꢆꢇꢅꢈ  
Figure 6b. Two-Tone Test. IN+ = –7dBFS 2kHz Sine,  
IN= –7dBFS 3.1kHz Sine, 32k Point FFT, fSMPL = 200ksps.  
Circuit Shown in Figure 6a  
Figure 6c. IN+/IN= –1dBFS 2kHz Fully Differential Sine,  
VCM = 0V, 32k Point FFT, fSMPL = 200ksps. Circuit Shown in  
Figure 6a  
True Bipolar Drive  
Unipolar Drive  
ꢀꢁꢂꢃꢄꢅꢆ RAꢇꢈ  
ꢀꢁ ꢂꢃ ꢄꢀꢅꢆꢇꢁ RAꢈꢉꢊ  
ꢀꢁR ꢂ ꢃꢄꢅꢆꢇꢈ  
ꢀꢁꢂ ꢃ ꢄꢅꢅꢅꢆꢇ  
ꢀꢁꢂAꢃ ꢄ ꢅꢆꢇꢈꢉꢊ  
ꢀꢁꢂR ꢃ ꢄꢄꢅꢆꢇ  
ꢀꢁR ꢂ ꢃꢄꢅꢄꢆꢇ  
ꢀꢁꢂ ꢃ ꢄꢅꢅꢆꢇꢈ  
ꢀꢁꢂAꢃ ꢄ ꢅꢆꢇꢅꢈꢉ  
ꢀꢁꢂR ꢃ ꢄꢄꢅꢆꢇ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂꢂ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢂ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁꢁ  
ꢀRꢁꢂꢃꢁꢄꢅꢆ ꢇꢈꢉꢊꢋ  
ꢀRꢁꢂꢃꢁꢄꢅꢆ ꢇꢈꢉꢊꢋ  
ꢀꢁꢂꢃꢄꢅ ꢆꢇꢅꢈ  
ꢀꢁꢂꢃꢄꢅ ꢆꢇꢅe  
Figure 6d. IN+ = –1dBFS 2kHz True Bipolar Sine, IN= 0V, 32k  
Point FFT, fSMPL = 200ksps. Circuit Shown in Figure 6a  
Figure 6e. IN+ = –1dBFS 2kHz Unipolar Sine, IN= 0V,  
32k Point FFT, fSMPL = 200ksps. Circuit Shown in Figure 6a  
Rev A  
23  
For more information www.analog.com  
LTC2358-16  
APPLICATIONS INFORMATION  
INTERNAL HI-Z BUFFERS  
ALLOW OPTIONAL  
ARBITRARY  
31V  
+
31V  
kΩ PASSIVE FILTERS  
LTC2057HV  
GAIN = 10  
LTC2057HV  
+
IN  
24V  
3.65k  
0.1µF  
BUFFERED  
ANALOG  
INPUTS  
2.49k  
V
+
CC  
COMMON MODE  
INPUT RANGE  
IN0  
IN0  
549Ω  
2.49k  
2.2nF  
LTC2358-16  
3.65k  
DIFFERENTIAL MODE  
INPUT RANGE: 500ꢀV  
+
V
REFBUF  
47µF  
REFIN  
EE  
0V  
BW = 10kHz  
IN  
0.1µF  
0.1µF  
–7V  
–7V  
ONLY CHANNEL 0 SHOWN FOR CLARITY  
235816 F07a  
Figure 7a. Amplify Differential Signals with Gain of 10  
Over a Wide Common Mode Range with Buffered Analog Inputs  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢀꢁ  
ꢀꢁꢁ  
ꢀꢁ  
ꢀꢁꢂ RAꢃꢄ  
ꢀꢁꢂ RAꢃꢄ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂꢅꢀꢀꢆRꢆꢇꢈꢅAꢂ ꢄRꢅꢉꢆ ꢊꢅꢇ ꢀ ꢁꢂꢃ   
ꢀꢁR ꢂ ꢃꢄꢅꢆꢇꢈ  
ꢀꢁꢂ ꢃ ꢄꢅꢅꢅꢆꢇ  
ꢀꢁꢂAꢃ ꢄ ꢅꢆꢇꢈꢉꢊ  
ꢀꢁꢂR ꢃ ꢄꢄꢅꢆꢇ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂꢂ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁ ꢀ ꢁꢂ ꢀ ꢁꢂ  
ꢀꢁꢂꢃ  
ꢀꢁꢀ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁꢁ  
ꢀꢁ  
ꢀꢁꢂ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁꢁ  
ꢀRꢁꢂꢃꢁꢄꢅꢆ ꢇꢈꢉꢊ  
ꢀRꢁꢂꢃꢁꢄꢅꢆ ꢇꢈꢉꢊꢋ  
ꢀꢁꢂꢃꢄꢅ ꢆꢇꢈꢉ  
ꢀꢁꢂꢃꢄꢅ ꢆꢇꢈꢉ  
Figure 7c. IN+/IN= 450mV 200Hz Fully  
Differential Sine, 0V ≤ VCM ≤ 24V, 32k Point FFT,  
fSMPL = 200ksps. Circuit Shown in Figure 7a  
Figure 7b. CMRR vs Input Frequency.  
Circuit Shown in Figure 7a  
15V  
0.1µF  
V
CC  
+
IN0  
IN0  
V
S1  
LTC2358-16  
+
IN1  
IN1  
R
SENSE  
I
SENSE  
V
REFBUF  
47µF  
REFIN  
EE  
V
S2  
0.1µF  
0.1µF  
–15V  
235816 F08  
ONLY CHANNELS 0 AND 1 SHOWN FOR CLARITY  
– V –10.24V ≤ V ≤ 10.24V  
V
R
S1  
S2  
S1  
I
=
SENSE  
–10.24V ≤ V ≤ 10.24V  
SENSE  
S2  
Figure 8. Simultaneously Sense Voltage (CH0) and Current (CH1) Over a Wide Common Mode Range  
Rev A  
24  
For more information www.analog.com  
LTC2358-16  
APPLICATIONS INFORMATION  
ADC REFERENCE  
ꢑꢀꢁꢂꢃꢒꢄꢅ  
Rꢓꢆꢖꢗ  
ꢀꢇꢎ  
ꢔAꢗꢙꢘAꢚ  
AsshownpreviouslyinTable1b, theLTC2358-16supports  
three reference configurations. The first uses both the in-  
ternalbandgapreferenceandreferencebuffer. Thesecond  
externally overdrives the internal reference but retains the  
internal buffer, which isolates the external reference from  
ADC conversion transients. This configuration is ideal  
for sharing a single precision external reference across  
multiple ADCs. The third disables the internal buffer and  
overdrives the REFBUF pin externally.  
RꢓꢆꢓRꢓꢗꢑꢓ  
ꢇꢍꢄꢌꢆ  
Rꢓꢆꢔꢕꢆ  
RꢓꢆꢓRꢓꢗꢑꢓ  
ꢔꢕꢆꢆꢓR  
ꢅꢍꢂꢎ  
ꢊꢋꢌꢆ  
ꢅꢍꢂꢎ  
ꢘꢗꢙ  
ꢀꢁꢂꢃꢄꢅ ꢆꢇꢈꢉ  
Figure 9a. Internal Reference with Internal  
Buffer Configuration  
Internal Reference with Internal Buffer  
The LTC2358-16 has an on-chip, low noise, low drift  
(20ppm/°C maximum), temperature compensated band-  
gap reference that is factory trimmed to 2.048V. The  
reference output connects through a 20kΩ resistor to  
the REFIN pin, which serves as the input to the on-chip  
reference buffer, as shown in Figure 9a. When employing  
the internal bandgap reference, the REFIN pin should be  
bypassed to GND (Pin 20) close to the pin with a 0.1μF  
ceramic capacitor to filter wideband noise. The reference  
ꢑꢀꢁꢂꢃꢒꢄꢅ  
Rꢓꢆꢖꢗ  
ꢀꢇꢎ  
ꢔAꢗꢙꢘAꢚ  
RꢓꢆꢓRꢓꢗꢑꢓ  
ꢀꢍꢋꢌꢆ  
Rꢓꢆꢔꢕꢆ  
RꢓꢆꢓRꢓꢗꢑꢓ  
ꢔꢕꢆꢆꢓR  
ꢅꢍꢂꢎ  
ꢊꢋꢌꢆ  
ꢑꢅꢅꢂꢂꢒꢀꢍꢇꢊꢃ  
ꢅꢍꢂꢎ  
buffer amplifies V  
to create the converter master  
REFIN  
reference voltage V  
ꢘꢗꢙ  
= 2 • V  
on the REFBUF pin,  
REFBUF  
REFIN  
ꢀꢁꢂꢃꢄꢅ ꢆꢇꢈꢉ  
nominally 4.096V when using the internal bandgap refer-  
ence. BypassREFBUFtoGND(Pin20)closetothepinwith  
at least a 47μF ceramic capacitor (X7R, 10V, 1210 size or  
X5R, 10V, 0805 size) to compensate the reference buffer,  
absorbtransientconversioncurrents,andminimizenoise.  
Figure 9b. External Reference with Internal  
Buffer Configuration  
ꢑꢀꢁꢂꢃꢒꢄꢅ  
ꢀꢇꢎ  
External Reference with Internal Buffer  
Rꢓꢆꢖꢗ  
ꢔAꢗꢙꢘAꢚ  
RꢓꢆꢓRꢓꢗꢑꢓ  
If more accuracy and/or lower drift is desired, REFIN can  
be easily overdriven by an external reference since 20kΩ  
of resistance separates the internal bandgap reference  
output from the REFIN pin, as shown in Figure 9b. The  
valid range of external reference voltage overdrive on the  
REFIN pin is 1.25V to 2.2V, resulting in converter master  
Rꢓꢆꢔꢕꢆ  
RꢓꢆꢓRꢓꢗꢑꢓ  
ꢔꢕꢆꢆꢓR  
ꢅꢍꢂꢎ  
ꢊꢋꢌꢆ  
ꢑꢅꢅꢂꢂꢒꢂ  
ꢅꢍꢂꢎ  
ꢘꢗꢙ  
reference voltages V  
between 2.5V and 4.4V, re-  
REFBUF  
ꢀꢁꢂꢃꢄꢅ ꢆꢇꢈꢉ  
spectively. Analog Devices, Inc. offers a portfolio of high  
performance references designed to meet the needs of  
manyapplications.Withitssmallsize,lowpower,andhigh  
accuracy,theLTC6655-2.048iswellsuitedforusewiththe  
LTC2358-16 when overdriving the internal reference. The  
Figure 9c. External Reference with Disabled  
Internal Buffer Configuration  
Rev A  
25  
For more information www.analog.com  
LTC2358-16  
APPLICATIONS INFORMATION  
LTC6655-2.048offers0.025%(maximum)initialaccuracy  
and2ppm/°C(maximum)temperaturecoefficientforhigh  
precision applications. The LTC6655-2.048 is fully speci-  
fied over the H-grade temperature range, complementing  
the extended temperature range of the LTC2358-16 up to  
125°C.BypassingtheLTC6655-2.048witha2.7µFto100µF  
ceramiccapacitorclosetotheREFINpinisrecommended.  
current step triggers a transient response in the external  
reference that must be considered, since any deviation in  
REFBUF  
is used to overdrive REFBUF, the fast settling LTC6655  
family of references is recommended.  
V
affectsconverteraccuracy.Ifanexternalreference  
Internal Reference Buffer Transient Response  
Foroptimumperformanceinapplicationsemployingburst  
sampling, the external reference with internal reference  
bufferconfigurationshouldbeused.Theinternalreference  
buffer incorporates a proprietary design that minimizes  
External Reference with Disabled Internal Buffer  
The internal reference buffer supports V  
= 4.4V  
REFBUF  
maximum. By grounding REFIN, the internal buffer may  
be disabled allowing REFBUF to be overdriven with an  
externalreferencevoltagebetween2.5Vand5V, asshown  
in Figure 9c. Maximum input signal swing and SNR are  
achieved by overdriving REFBUF using an external 5V  
reference. The buffer feedback resistors load the REFBUF  
pin with 13kΩ even when the reference buffer is disabled.  
The LTC6655-5 offers the same small size, accuracy, drift,  
and extended temperature range as the LTC6655-2.048,  
and achieves a typical SNR of 94.8dB when paired with  
the LTC2358-16. Bypass the LTC6655-5 to GND (Pin 20)  
close to the REFBUF pin with at least a 47μF ceramic ca-  
pacitor (X7R, 10V, 1210 size or X5R, 10V, 0805 size) to  
absorb transient conversion currents and minimize noise.  
movements in V  
when responding to a burst of  
REFBUF  
conversions following an idle period. Figure 11 compares  
the burst conversion response of the LTC2358-16 with an  
input near full scale for two reference configurations. The  
first configuration employs the internal reference buffer  
with REFIN externally overdriven by an LTC6655-2.048,  
while the second configuration disables the internal ref-  
erence buffer and overdrives REFBUF with an external  
LTC6655-4.096. In both cases REFBUF is bypassed to  
GND with a 47µF ceramic capacitor.  
ꢀꢁꢂꢁ  
ꢀꢁꢂꢃꢄꢅꢆ RAꢇꢈ  
ꢀꢁ ꢀ ꢁꢂꢃ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁ ꢀ ꢁꢂ  
The LTC2358-16 converter draws a charge (Q  
) from  
CONV  
ꢀꢁꢂꢀRꢃAꢄ RꢀꢅꢀRꢀꢃꢆꢀ ꢇꢃ Rꢀꢅꢈꢉꢅ  
the REFBUF pin during each conversion cycle. On short  
time scales most of this charge is supplied by the external  
REFBUF bypass capacitor, but on longer time scales all of  
the charge is supplied by either the reference buffer, or  
when the internal reference buffer is disabled, the external  
reference. This charge draw corresponds to a DC current  
ꢀꢁꢂꢃRꢁAꢄ RꢃꢅꢃRꢃꢁꢆꢃ ꢇꢈꢅꢅꢃR  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢁ  
ꢀꢁꢁ  
ꢀꢁꢁ  
ꢀꢁꢁ  
ꢀꢁꢁ  
equivalentofI  
=Q  
•f  
,whichisproportional  
REFBUF  
CONV SMPL  
ꢀꢁꢂꢃ ꢄꢅꢆꢇ  
ꢀꢁꢂꢃꢄꢅ ꢆꢄꢄ  
to sample rate. In applications where a burst of samples  
is taken after idling for long periods of time, as shown in  
Figure 11. Burst Conversion Response of the LTC2358-16,  
fSMPL = 200ksps  
Figure 10, I  
quickly transitions from approximately  
REFBUF  
0.4mA to 1.5mA (V  
= 5V, f  
= 200kHz). This  
REFBUF  
SMPL  
ꢀꢁꢂ  
ꢉꢊꢋꢌꢍꢎ ꢏꢍꢐ  
ꢃꢄꢅꢆ  
ꢇꢆRꢃꢈꢄ  
ꢃꢄꢅꢆ  
ꢇꢆRꢃꢈꢄ  
Figure 10. CNV Waveform Showing Burst Sampling  
Rev A  
26  
For more information www.analog.com  
LTC2358-16  
APPLICATIONS INFORMATION  
DYNAMIC PERFORMANCE  
through Nth harmonics, respectively. Figure 12 shows  
that the LTC2358-16 achieves a typical THD of –111dB  
(N = 6) in the 10.24V range at a 200kHz sampling rate  
with a true bipolar 2kHz input signal.  
Fast Fourier transform (FFT) techniques are used to test  
the ADC’s frequency response, distortion, and noise at the  
rated throughput. By applying a low distortion sine wave  
and analyzing the digital output using an FFT algorithm,  
the ADC’s spectral content can be examined for frequen-  
cies outside the fundamental. The LTC2358-16 provides  
guaranteed tested limits for both AC distortion and noise  
measurements.  
ꢀꢁꢂꢃꢄꢅꢆ RAꢇꢈ  
ꢀꢁR ꢂ ꢃꢄꢅꢆꢇꢈ  
ꢀꢁꢂ ꢃ ꢄꢅꢅꢅꢆꢇ  
ꢀꢁꢂAꢃ ꢄ ꢅꢆꢇꢈꢉꢊ  
ꢀꢁꢂR ꢃ ꢄꢄꢅꢆꢇ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢂꢂ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
ꢀꢁꢂꢃ  
Signal-to-Noise and Distortion Ratio (SINAD)  
The signal-to-noise and distortion ratio (SINAD) is the  
ratiobetweentheRMSamplitudeofthefundamentalinput  
frequency and the RMS amplitude of all other frequency  
components at the A/D output. The output is band-limited  
to frequencies below half the sampling frequency, exclud-  
ing DC. Figure 12 shows that the LTC2358-16 achieves a  
typical SINAD of 94.1dB in the 10.24V range at a 200kHz  
sampling rate with a true bipolar 2kHz input signal.  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁꢁ  
ꢀRꢁꢂꢃꢁꢄꢅꢆ ꢇꢈꢉꢊꢋ  
ꢀꢁꢂꢃꢄꢅ ꢆꢄꢀ  
Figure 12. 32k Point FFT fSMPL = 200ksps, fIN = 2kHz  
POWER CONSIDERATIONS  
The LTC2358-16 requires four power supplies: the posi-  
Signal-to-Noise Ratio (SNR)  
tive and negative high voltage power supplies (V and  
CC  
V ), the 5V core power supply (V ) and the digital input/  
EE  
DD  
The signal-to-noise ratio (SNR) is the ratio between the  
RMS amplitude of the fundamental input frequency and  
the RMS amplitude of all other frequency components  
except the first five harmonics and DC. Figure 12 shows  
that the LTC2358-16 achieves a typical SNR of 94.2dB in  
the 10.24V range at a 200kHz sampling rate with a true  
bipolar 2kHz input signal.  
output (I/O) interface power supply (OV ). As long as  
DD  
CC  
the voltage difference limits of 10V ≤ V – V ≤ 38V  
EE  
are observed, V and V may be independently biased  
CC  
EE  
anywhere within their own individual allowed operating  
ranges, including the ability for V to be tied directly to  
EE  
ground. This feature enables the common mode input  
range of the LTC2358-16 to be tailored to the specific  
application’s requirements. The flexible OV supply al-  
DD  
Total Harmonic Distortion (THD)  
lows the LTC2358-16 to communicate with CMOS logic  
Totalharmonicdistortion(THD)istheratiooftheRMSsum  
ofallharmonicsoftheinputsignaltothefundamentalitself.  
The out-of-band harmonics alias into the frequency band  
between DC and half the sampling frequency (f  
THD is expressed as:  
operating between 1.8V and 5V, including 2.5V and 3.3V  
systems. When using LVDS I/O mode, the range of OV  
is 2.375V to 5.25V.  
DD  
/2).  
SMPL  
Power Supply Sequencing  
The LTC2358-16 does not have any specific power supply  
sequencing requirements. Care should be taken to adhere  
to the maximum voltage relationships described in the  
Absolute Maximum Ratings section. The LTC2358-16 has  
an internal power-on-reset (POR) circuit which resets the  
2
2
2
2
V + V + V ...V  
N
2
3
4
THD = 20log  
V
1
where V is the RMS amplitude of the fundamental fre-  
quencyandV throughV aretheamplitudesofthesecond  
1
2
N
Rev A  
27  
For more information www.analog.com  
LTC2358-16  
APPLICATIONS INFORMATION  
converter on initial power-up and whenever V drops  
sion process. The CNV timing required to take advantage  
of the reduced power nap mode of operation is described  
in the Nap Mode section.  
DD  
below 2V. Once the supply voltage re-enters the nominal  
supply voltage range, the POR reinitializes the ADC. No  
conversions should be initiated until at least 10ms after  
a POR event to ensure the initialization period has ended.  
Whenemployingtheinternalreferencebuffer,allow200ms  
forthebuffertopowerupandrechargetheREFBUFbypass  
capacitor. Any conversion initiated before these times will  
produce invalid results.  
Internal Conversion Clock  
The LTC2358-16 has an internal clock that is trimmed to  
achieve a maximum conversion time of 550•N ns with N  
channels enabled. With a minimum acquisition time of  
570ns when converting eight channels simultaneously,  
throughputperformanceof200kspsisguaranteedwithout  
any external adjustments. Also note that the minimum  
TIMING AND CONTROL  
CNV Timing  
acquisition time varies with sampling frequency (f  
and the number of enabled channels.  
)
SMPL  
The LTC2358-16 sampling and conversion is controlled  
by CNV. A rising edge on CNV transitions all channels’ S/H  
circuits from track mode to hold mode, simultaneously  
sampling the input signals on all channels and initiating  
a conversion. Once a conversion has been started, it  
cannot be terminated early except by resetting the ADC,  
as discussed in the Reset Timing section. For optimum  
performance, drive CNV with a clean, low jitter signal and  
avoid transitions on data I/O lines leading up to the rising  
edge of CNV. Additionally, to minimize channel-to-channel  
crosstalk, avoid high slew rates on the analog inputs for  
100ns before and after the rising edge of CNV. Converter  
status is indicated by the BUSY output, which transitions  
low-to-high at the start of each conversion and stays high  
untiltheconversioniscomplete.OnceCNVisbroughthigh  
to begin a conversion, it should be returned low between  
40ns and 60ns later or after the falling edge of BUSY to  
minimizeexternaldisturbancesduringtheinternalconver-  
Nap Mode  
The LTC2358-16 can be placed into nap mode after a con-  
versionhasbeencompletedtoreducepowerconsumption  
between conversions. In this mode a portion of the device  
circuitry is turned off, including circuits associated with  
sampling the analog input signals. Nap mode is enabled  
by keeping CNV high between conversions, as shown in  
Figure 13. To initiate a new conversion after entering nap  
mode, bring CNV low and hold for at least 750ns before  
bringingithighagain.Theconverteracquisitiontime(t  
is set by the CNV low time (t  
)
ACQ  
) when using nap mode.  
CNVL  
Power Down Mode  
When PD is brought high, the LTC2358-16 is powered  
down and subsequent conversion requests are ignored. If  
this occurs during a conversion, the device powers down  
once the conversion completes. In this mode, the device  
ꢀꢁꢂꢎ  
ꢀꢁꢂ  
ꢀꢄꢁꢂ  
ꢆꢇꢈꢉ  
ꢁAꢊ  
Aꢀꢅ  
ꢁAꢊ ꢋꢄꢌꢍ  
ꢏꢐꢑꢒꢓꢔ ꢕꢓꢐ  
Figure 13. Nap Mode Timing for the LTC2358-16  
Rev A  
28  
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LTC2358-16  
APPLICATIONS INFORMATION  
draws only a small regulator standby current resulting in a  
typical power dissipation of 0.68mW. To exit power down  
mode, bring the PD pin low and wait at least 10ms before  
initiatingaconversion. When employingtheinternal refer-  
ence buffer, allow 200ms for the buffer to power up and  
recharge the REFBUF bypass capacitor. Any conversion  
initiated before these times will produce invalid results.  
reduced, as shown in Figure 15. This decrease in aver-  
age power dissipation occurs because a portion of the  
LTC2358-16 circuitry is turned off during nap mode, and  
the fraction of the conversion cycle (t ) spent napping  
CYC  
increasesasthesamplingfrequency(f  
)isdecreased.  
SMPL  
ꢀꢁ  
ꢀꢁꢂꢃ ꢄAꢅ ꢆꢇꢈꢉ  
ꢀꢁꢂꢃ  
ꢀꢁ  
ꢀ ꢁꢂꢃ  
ꢀꢁꢁ  
ꢀꢁ  
ꢀꢁ  
Reset Timing  
A global reset of the LTC2358-16, equivalent to a power-  
on-reset event, may be executed without needing to cycle  
the supplies. This feature is useful when recovering from  
system-level events that require the state of the entire sys-  
tem to be reset to a known synchronized value. To initiate  
a global reset, bring PD high twice without an intervening  
conversion, as shown in Figure 14. The reset event is trig-  
geredonthesecondrisingedgeofPD,andasynchronously  
ends based on an internal timer. Reset clears all serial data  
outputregistersandrestorestheinternalSoftSpanconfigu-  
ration register default state of all channels in SoftSpan 7.  
If reset is triggered during a conversion, the conversion  
is immediately halted. The normal power down behavior  
associatedwithPDgoinghighisnotaffectedbyreset.Once  
PD is brought low, wait at least 10ms before initiating a  
conversion. When employing the internal reference buffer,  
allow 200ms for the buffer to power up and recharge the  
REFBUF bypass capacitor. Any conversion initiated before  
these times will produce invalid results.  
ꢀꢁꢁ  
ꢀꢁꢂꢂ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁꢁ  
ꢀꢁ  
ꢀꢁ  
ꢀꢁꢂ  
ꢀꢁꢂ  
ꢀꢁꢁ  
ꢀAꢁꢂꢃꢄꢅꢆ ꢇRꢈꢉꢊꢈꢅꢋꢌ ꢍꢎꢏꢐꢑ  
ꢀꢁꢂꢃꢄꢅ ꢆꢄꢂ  
Figure 15. Power Dissipation of the LTC2358-16  
Decreases with Decreasing Sampling Frequency  
DIGITAL INTERFACE  
TheLTC2358-16featuresCMOSandLVDSserialinterfaces,  
selectable using the LVDS/CMOS pin. The flexible OV  
DD  
supply allows the LTC2358-16 to communicate with any  
CMOS logic operating between 1.8V and 5V, including  
2.5V and 3.3V systems, while the LVDS interface supports  
low noise digital designs. In CMOS mode, applications  
may employ between one and eight lanes of serial data  
output, allowing the user to optimize bus width and data  
throughput. Together, these I/O interface options enable  
the LTC2358-16 to communicate equally well with legacy  
microcontrollers and modern FPGAs.  
Power Dissipation vs Sampling Frequency  
When nap mode is employed, the power dissipation of  
the LTC2358-16 decreases as the sampling frequency is  
ꢆꢇꢅ  
ꢆꢇ  
ꢓAꢔꢍ  
ꢆꢇꢈ  
ꢀꢁꢂꢅ  
ꢀꢁꢂ  
ꢋꢍꢀꢄꢁꢇ Rꢏꢋꢏꢁꢑ ꢍꢇꢑꢍ ꢄꢒ  
ꢆꢇ ꢎRꢏꢑꢑꢍRꢋ Rꢍꢋꢍꢎ  
ꢉꢊꢋꢌ  
ꢀꢄꢁꢂ  
Rꢍꢋꢍꢎ ꢎꢏꢐꢍ  
ꢋꢍꢎ ꢏꢁꢎꢍRꢁAꢈꢌ  
Rꢍꢋꢍꢎ  
ꢕꢖꢗꢘꢙꢚ ꢒꢙꢛ  
Figure 14. Reset Timing for the LTC2358-16  
Rev A  
29  
For more information www.analog.com  
LTC2358-16  
APPLICATIONS INFORMATION  
CS ꢏ ꢐꢌ ꢏ ꢃ  
ꢄAꢜꢐꢝꢔ ꢍ  
ꢄAꢜꢐꢝꢔ ꢍ ꢟ ꢂ  
ꢀꢙꢀ  
ꢀꢍꢎꢢ  
ꢀꢍꢎ  
ꢀꢍꢎꢝ  
ꢗꢘꢄꢙ  
Aꢀꢖ  
ꢀꢑꢍꢎ  
Rꢔꢀꢑꢜꢜꢔꢍꢌꢔꢌ ꢌAꢓA ꢓRAꢍꢄAꢀꢓꢛꢑꢍ ꢞꢛꢍꢌꢑꢞ  
ꢗꢘꢄꢙꢝꢢ  
ꢖꢘꢛꢔꢓ  
ꢄꢄꢌꢛꢄꢀꢚꢛ  
ꢄꢀꢚꢛ  
ꢄꢀꢚꢛꢢ  
ꢄꢀꢚꢛ  
ꢄꢌꢛ  
ꢋ ꢂꢃ ꢂꢂ ꢂꢁ ꢂꢅ ꢂꢆ ꢂꢇ ꢂꢈ ꢂꢉ ꢂꢊ ꢂꢋ ꢁꢃ ꢁꢂ ꢁꢁ ꢁꢅ ꢁꢆ  
ꢢꢄꢌꢛꢄꢀꢚꢛ  
ꢄꢀꢚꢛꢝ  
ꢌꢑꢍARꢔ  
ꢄꢁꢅ ꢁꢁ ꢄꢁꢂ ꢄꢁꢃ ꢄꢂꢋ ꢄꢂꢊ ꢄꢂꢉ ꢄꢂꢈ ꢄꢂꢇ ꢄꢂꢆ ꢄꢂꢅ ꢄꢂꢁ ꢄꢂꢂ ꢄꢂꢃ  ꢄꢊ ꢄꢉ ꢄꢈ ꢄꢇ ꢄꢆ ꢄꢅ ꢄꢁ ꢄꢂ ꢄꢃ  
ꢄꢑꢠꢓꢄꢐAꢍ ꢀꢑꢍꢠꢛꢡꢘRAꢓꢛꢑꢍ ꢞꢑRꢌ ꢠꢑR ꢀꢑꢍꢎꢔRꢄꢛꢑꢍ ꢍ ꢟ ꢂ  
ꢄꢚꢔꢞ  
ꢌꢄꢌꢑꢗꢘꢄꢙꢝ  
ꢢꢄꢌꢑꢄꢀꢚꢛ  
ꢄꢀꢚꢑ  
ꢄꢌꢑꢃ  
ꢌꢄꢌꢑꢄꢀꢚꢛ  
ꢌꢑꢍARꢔ  
ꢌꢑꢍARꢔ  
ꢌꢂꢇ  
ꢌꢂꢇ  
ꢌꢂꢆ ꢌꢂꢅ ꢌꢂꢁ ꢌꢂꢂ ꢌꢂꢃ  ꢌꢊ ꢌꢉ ꢌꢈ ꢌꢇ ꢌꢆ ꢌꢅ ꢌꢁ ꢌꢂ ꢌꢃ  
ꢀꢑꢍꢎꢔRꢄꢛꢑꢍ Rꢔꢄꢘꢓ  
ꢀꢁ ꢀꢂ ꢀꢃ ꢄꢁ ꢄꢄꢂ ꢄꢄꢃ ꢌꢂꢇ  
ꢀꢢAꢍꢍꢔꢝ ꢛꢌ ꢄꢑꢠꢓꢄꢐAꢍ  
ꢀꢑꢍꢎꢔRꢄꢛꢑꢍ Rꢔꢄꢘꢓ  
ꢀꢢAꢍꢍꢔꢝ ꢃ  
ꢁꢆꢣꢗꢛꢓ ꢐAꢀꢚꢔꢓ  
ꢀꢑꢍꢎꢔRꢄꢛꢑꢍ ꢍ  
ꢀꢢAꢍꢍꢔꢝ ꢂ  
ꢁꢆꢣꢗꢛꢓ ꢐAꢀꢚꢔꢓ  
ꢀꢑꢍꢎꢔRꢄꢛꢑꢍ ꢍ  
ꢄꢌꢑꢉ  
ꢌꢂꢆ ꢌꢂꢅ ꢌꢂꢁ ꢌꢂꢂ ꢌꢂꢃ  ꢌꢊ ꢌꢉ ꢌꢈ ꢌꢇ ꢌꢆ ꢌꢅ ꢌꢁ ꢌꢂ ꢌꢃ  
ꢀꢑꢍꢎꢔRꢄꢛꢑꢍ Rꢔꢄꢘꢓ  
ꢀꢁ ꢀꢂ ꢀꢃ ꢄꢁ ꢄꢄꢂ ꢄꢄꢃ ꢌꢂꢇ  
ꢀꢢAꢍꢍꢔꢝ ꢛꢌ ꢄꢑꢠꢓꢄꢐAꢍ ꢀꢑꢍꢎꢔRꢄꢛꢑꢍ Rꢔꢄꢘꢓ  
ꢀꢢAꢍꢍꢔꢝ ꢉ  
ꢁꢆꢣꢗꢛꢓ ꢐAꢀꢚꢔꢓ  
ꢀꢑꢍꢎꢔRꢄꢛꢑꢍ ꢍ  
ꢀꢢAꢍꢍꢔꢝ ꢃ  
ꢁꢆꢣꢗꢛꢓ ꢐAꢀꢚꢔꢓ  
ꢀꢑꢍꢎꢔRꢄꢛꢑꢍ ꢍ  
ꢁꢅꢇꢊꢂꢈ ꢠꢂꢈ  
Figure 16. Serial CMOS I/O Mode  
Serial CMOS I/O Mode  
configuration words are only accepted within this recom-  
mended data transaction window, but SoftSpan changes  
take effect immediately with no additional analog input  
settling time required before starting the next conversion.  
It is still possible to read conversion data after starting the  
nextconversion,butthiswilldegradeconversionaccuracy  
and therefore is not recommended.  
As shown in Figure 16, in CMOS I/O mode the serial data  
bus consists of a serial clock input, SCKI, serial data  
input, SDI, serial clock output, SCKO, and eight lanes of  
serial data output, SDO0 to SDO7. Communication with  
the LTC2358-16 across this bus occurs during predefined  
data transaction windows. Within a window, the device  
accepts 24-bit SoftSpan configuration words for the next  
conversion on SDI and outputs 24-bit packets containing  
conversion results and channel configuration information  
from the previous conversion on SDO0 to SDO7. New  
data transaction windows open 10ms after powering up  
or resetting the LTC2358-16, and at the end of each con-  
version on the falling edge of BUSY. In the recommended  
use case, the data transaction should be completed with  
Just prior to the falling edge of BUSY and the opening of  
a new data transaction window, SCKO is forced low and  
SDO0 to SDO7 are updated with the latest conversion  
results from analog input channels 0 to 7, respectively.  
Rising edges on SCKI serially clock conversion results  
and analog input channel configuration information out  
on SDO0 to SDO7 and trigger transitions on SCKO that are  
skew-matchedtothedataonSDO0toSDO7. Theresulting  
SCKO frequency is half that of SCKI. SCKI rising edges  
also latch SoftSpan configuration words provided on SDI,  
a minimum t  
time of 20ns prior to the start of the  
QUIET  
next conversion, as shown in Figure 16. New SoftSpan  
Rev A  
30  
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LTC2358-16  
APPLICATIONS INFORMATION  
which are used to program the internal 24-bit SoftSpan  
configuration register. See the section Programming the  
SoftSpan Configuration Register in CMOS I/O Mode for  
further details. SCKI is allowed to idle either high or low  
in CMOS I/O mode. As shown in Figure 17, the CMOS  
bus is enabled when CS is low and is disabled and Hi-Z  
when CS is high, allowing the bus to be shared across  
multiple devices.  
When interfacing the LTC2358-16 with a standard SPI  
bus, capture output data at the receiver on rising edges of  
SCKI. SCKO is not used in this case. Multiple SDO lanes  
are also usually not useful in this case. In other applica-  
tions, such as interfacing the LTC2358-16 with an FPGA  
or CPLD, rising and falling edges of SCKO may be used  
to capture serial output data on SDO0 to SDO7 in double  
data rate (DDR) fashion. Capturing data using SCKO adds  
robustnesstodelayvariationsovertemperatureandsupply.  
ThedataonSDO0toSDO7aregroupedinto24-bitpackets  
consisting of a 16-bit conversion result followed by two  
zeros,3-bitanalogchannelID,and3-bitSoftSpancode,all  
presented MSB first. As suggested in Figures 16 and 17,  
each SDO lane outputs these packets for all analog input  
channels in a sequential, circular manner. For example,  
the first 24-bit packet output on SDO0 corresponds to  
analog input channel 0, followed by the packets for chan-  
nels 1 through 7. The data output on SDO0 then wraps  
back to channel 0, and this pattern repeats indefinitely.  
Other SDO lanes follow a similar circular pattern, except  
the first packet presented on each lane corresponds to  
its associated analog input channel.  
Full Eight Lane Serial CMOS Output Data Capture  
As shown in Table 2, full 200ksps per channel throughput  
canbeachievedwitha45MHzSCKIfrequencybycapturing  
the first packet (24 SCKI cycles total) from all eight serial  
data output lanes SDO0 to SDO7. This configuration also  
allowsconversionresultsfromallchannelstobecaptured  
using as few as 16 SCKI cycles if the 3-bit analog channel  
ID and 3-bit SoftSpan code are not needed and the device  
SoftSpan configuration is not being changed. Multi-lane  
data capture is usually best suited for use with FPGA  
or CPLD capture hardware, but may be useful in other  
application-specific cases.  
ꢀꢁ ꢂ ꢃ  
ꢊꢋꢌꢍ  
CS  
ꢌꢈꢏꢐ ꢁꢄꢅ ARꢉ  
ꢁꢄꢅARꢉ  
ꢅꢉꢟ ꢌꢠꢡꢢꢌꢣꢤꢥ ꢈꢄꢅꢗꢐꢦꢋRAꢇꢐꢄꢅ ꢟꢄRꢁ  
ꢌꢁꢐ ꢁꢄꢅ ARꢉ  
ꢇꢟꢄ AꢜꢜꢚꢛꢉRꢄ ꢟꢄRꢁꢌ Aꢅꢁ ꢄꢅꢉ ꢀARꢇꢐAꢜ ꢟꢄRꢁ  
ꢁꢄꢅARꢉ  
ꢝꢄꢧꢉRꢟRꢐꢇꢉꢌ ꢐꢅꢇꢉRꢅAꢜ ꢈꢄꢅꢗꢐꢦ RꢉꢦꢐꢌꢇꢉRꢞ  
ꢝꢐꢅꢇꢉRꢅAꢜ ꢈꢄꢅꢗꢐꢦ RꢉꢦꢐꢌꢇꢉR RꢉꢇAꢐꢅꢌ ꢈꢋRRꢉꢅꢇ ꢧAꢜꢋꢉꢞ  
ꢘꢙꢚꢛ  
ꢘꢙꢚꢛ  
ꢌꢈꢏꢄ  
ꢘꢙꢚꢛ  
ꢘꢙꢚꢛ  
ꢁꢐꢌ  
ꢈꢘAꢅꢅꢉꢜ ꢒ ꢀAꢈꢏꢉꢇ  
ꢝꢀARꢇꢐAꢜꢞ  
ꢌꢁꢄꢃ  
ꢈꢘAꢅꢅꢉꢜ ꢃ ꢀAꢈꢏꢉꢇ  
ꢈꢘAꢅꢅꢉꢜ ꢎ ꢀAꢈꢏꢉꢇ  
ꢈꢘAꢅꢅꢉꢜ ꢕ ꢀAꢈꢏꢉꢇ  
ꢈꢘAꢅꢅꢉꢜ ꢃ ꢀAꢈꢏꢉꢇ  
ꢈꢘAꢅꢅꢉꢜ ꢑ ꢀAꢈꢏꢉꢇ  
ꢈꢘAꢅꢅꢉꢜ ꢕ ꢀAꢈꢏꢉꢇ  
ꢉꢅ  
ꢘꢙꢚꢛ  
ꢘꢙꢚꢛ  
ꢈꢘAꢅꢅꢉꢜ ꢑ ꢀAꢈꢏꢉꢇ  
ꢝꢀARꢇꢐAꢜꢞ  
ꢌꢁꢄꢎ  
ꢑꢒꢓꢔꢕꢖ ꢗꢕꢎ  
Figure 17. Internal SoftSpan Configuration Register Behavior. Serial CMOS Bus Response to CS  
Rev A  
31  
For more information www.analog.com  
LTC2358-16  
APPLICATIONS INFORMATION  
Fewer Than Eight Lane Serial CMOS Output Data Capture  
Programming the SoftSpan Configuration Register in  
CMOS I/O Mode  
Applications that cannot accommodate the full eight lanes  
of serial data capture may employ fewer lanes without  
reconfiguring the LTC2358-16. For example, capturing  
the first two packets (48 SCKI cycles total) from SDO0,  
SDO2, SDO4, and SDO6 provides data for analog input  
channels 0 and 1, 2 and 3, 4 and 5, and 6 and 7, respec-  
tively,usingfouroutputlanes.Similarly,capturingthefirst  
four packets (96 SCKI cycles total) from SDO0 and SDO4  
provides data for analog input channels 0 to 3 and 4 to  
7, respectively, using two output lanes. If only one lane  
can be accommodated, capturing the first eight packets  
(192 SCKI cycles total) from SDO0 provides data for all  
analog input channels. As shown in Table 2, full 200ksps  
per channel throughput can be achieved with a 90MHz  
SCKI frequency in the four lane case, but the maximum  
CMOS SCKI frequency of 100MHz limits the throughput  
to less than 200ksps per channel in the two lane and one  
lane cases. Finally, note that in choosing the number of  
lanes and which lanes to use for data capture, the user is  
notrestrictedtothespecificcasesmentionedabove.Other  
choices may be more optimal in particular applications.  
The internal 24-bit SoftSpan configuration register con-  
trols the SoftSpan range for all analog input channels of  
the LTC2358-16. The default state of this register after  
power-up or resetting the device is all ones, configuring  
each channel to convert in SoftSpan 7, the 2.5 • V  
REFBUF  
range (see Table 1a). The state of this register may be  
modifiedbyprovidinganew24-bitSoftSpanconfiguration  
word on SDI during the data transaction window shown  
in Figure 16. New SoftSpan configuration words are only  
accepted within this recommended data transaction win-  
dow, but SoftSpan changes take effect immediately with  
no additional analog input settling time required before  
starting the next conversion. Setting a channel’s SoftSpan  
code to SS[2:0] = 000 immediately disables the channel,  
resultinginacorrespondingreductionint  
onthenext  
CONV  
conversion.Similarly,enablingapreviouslydisabledchan-  
nelrequiresnoadditionalanaloginputsettlingtimebefore  
starting the next conversion. The mapping between the  
serial SoftSpan configuration word, the internal SoftSpan  
configuration register, and each channel’s 3-bit SoftSpan  
code is illustrated in Figure 18.  
Table 2. Required SCKI Frequency to Achieve Various Throughputs in Common Output Bus Configurations with Eight Channels Enabled.  
Shaded Entries Denote Throughputs That Are Not Achievable in a Given Configuration. Calculated Using fSCKI = (Number of SCKI  
Cycles)/(tACQ(MIN) – tQUIET  
)
REQUIRED f  
200ksps/CHANNEL  
(tACQ = 570ns)  
(MHz) TO ACHIEVE THROUGHPUT OF  
SCKI  
NUMBER OF SDO  
LANES  
NUMBER OF SCKI  
CYCLES  
I/O MODE  
100ksps/CHANNEL  
(tACQ = 5570ns)  
50ksps/CHANNEL  
(tACQ = 15570ns)  
8
8
4
2
1
1
16  
24  
30  
45  
3
2
5
2
CMOS  
LVDS  
48  
90  
9
4
96  
Not Achievable  
Not Achievable  
180 (360Mbps)  
18  
35  
7
13  
192  
96  
18 (36Mbps)  
7 (14Mbps)  
Rev A  
32  
For more information www.analog.com  
LTC2358-16  
APPLICATIONS INFORMATION  
CMOS I/O MODE  
ꢀꢀꢋꢓꢀꢐꢒꢓ  
ꢀꢐꢒꢓ  
ꢀꢐꢒꢓꢢ  
ꢀꢐꢒꢓ  
ꢀꢋꢓ  
ꢃꢊ ꢃꢃ ꢃꢁ ꢃꢂ ꢃꢄ ꢃꢅ ꢃꢆ ꢃꢇ ꢃꢈ ꢃꢉ ꢁꢊ ꢁꢃ ꢁꢁ ꢁꢂ ꢁꢄ  
ꢢꢀꢋꢓꢀꢐꢒꢓ  
ꢀꢐꢒꢓꢟ  
ꢋꢌꢍARꢑ  
ꢀꢁꢂ ꢁꢁ ꢀꢁꢃ ꢀꢁꢊ ꢀꢃꢉ ꢀꢃꢈ ꢀꢃꢇ ꢀꢃꢆ ꢀꢃꢅ ꢀꢃꢄ ꢀꢃꢂ ꢀꢃꢁ ꢀꢃꢃ ꢀꢃꢊ  ꢀꢈ ꢀꢇ ꢀꢆ ꢀꢅ ꢀꢄ ꢀꢂ ꢀꢁ ꢀꢃ ꢀꢊ  
ꢀꢔꢕꢖꢀꢗꢘꢙ ꢐꢌꢍꢚꢓꢛꢜRAꢏꢓꢌꢍ ꢝꢌRꢋ  
LVDS I/O MODE  
ꢀꢐꢒꢓ  
ꢀꢐꢒꢓꢢ  
ꢀꢐꢒꢓ  
ꢋꢀꢡ  
ꢃꢊ ꢃꢃ ꢃꢁ ꢃꢂ ꢃꢄ ꢃꢅ ꢃꢆ ꢃꢇ ꢃꢈ ꢃꢉ ꢁꢊ ꢁꢃ ꢁꢁ ꢁꢂ ꢁꢄ  
ꢢꢀꢋꢓꢀꢐꢒꢓ  
ꢀꢐꢒꢓꢟ  
ꢀꢀꢋꢓꢀꢐꢒꢓ  
ꢀꢀꢋꢓꢀꢐꢒꢓ  
ꢢꢀꢋꢓꢀꢐꢒꢓ  
ꢀꢋꢓ  
ꢋꢀꢡ  
ꢋꢌꢍARꢑ  
ꢀꢁꢂ ꢁꢁ ꢀꢁꢃ ꢀꢁꢊ ꢀꢃꢉ ꢀꢃꢈ ꢀꢃꢇ ꢀꢃꢆ ꢀꢃꢅ ꢀꢃꢄ ꢀꢃꢂ ꢀꢃꢁ ꢀꢃꢃ ꢀꢃꢊ  ꢀꢈ ꢀꢇ ꢀꢆ ꢀꢅ ꢀꢄ ꢀꢂ ꢀꢁ ꢀꢃ ꢀꢊ  
ꢀꢔꢕꢖꢀꢗꢘꢙ ꢐꢌꢍꢚꢓꢛꢜRAꢏꢓꢌꢍ ꢝꢌRꢋ  
INTERNAL 24-BIT SoftSpan CONFIGURATION REGISTER  
(SAME FOR CMOS AND LVDS)  
ꢁꢂ  
ꢐꢢAꢍꢍꢑꢟ ꢇ ꢀꢔꢕꢖꢀꢗꢘꢙ ꢐꢢAꢍꢍꢑꢟ ꢆ ꢀꢔꢕꢖꢀꢗꢘꢙ ꢐꢢAꢍꢍꢑꢟ ꢅ ꢀꢔꢕꢖꢀꢗꢘꢙ ꢐꢢAꢍꢍꢑꢟ ꢄ ꢀꢔꢕꢖꢀꢗꢘꢙ ꢐꢢAꢍꢍꢑꢟ ꢂ ꢀꢔꢕꢖꢀꢗꢘꢙ ꢐꢢAꢍꢍꢑꢟ ꢁ ꢀꢔꢕꢖꢀꢗꢘꢙ ꢐꢢAꢍꢍꢑꢟ ꢃ ꢀꢔꢕꢖꢀꢗꢘꢙ ꢐꢢAꢍꢍꢑꢟ ꢊ ꢀꢔꢕꢖꢀꢗꢘꢙ  
ꢐꢌꢋꢑ ꢀꢀꢣꢁꢤꢊꢥ ꢐꢌꢋꢑ ꢀꢀꢣꢁꢤꢊꢥ ꢐꢌꢋꢑ ꢀꢀꢣꢁꢤꢊꢥ ꢐꢌꢋꢑ ꢀꢀꢣꢁꢤꢊꢥ ꢐꢌꢋꢑ ꢀꢀꢣꢁꢤꢊꢥ ꢐꢌꢋꢑ ꢀꢀꢣꢁꢤꢊꢥ ꢐꢌꢋꢑ ꢀꢀꢣꢁꢤꢊꢥ ꢐꢌꢋꢑ ꢀꢀꢣꢁꢤꢊꢥ  
ꢁꢁ  
ꢁꢃ  
ꢁꢊ  
ꢃꢉ  
ꢃꢈ  
ꢃꢇ  
ꢃꢆ  
ꢃꢅ  
ꢃꢄ  
ꢃꢂ  
ꢃꢁ  
ꢃꢃ  
ꢃꢊ  
ꢁꢂꢅꢈꢃꢆ ꢚꢃꢈ  
Figure 18. Mapping Between Serial SoftSpan Configuration Word, Internal SoftSpan  
Configuration Register, and SoftSpan Code for Each Analog Input Channel  
Iffewerthan24SCKIrisingedgesareprovidedduringadata  
transactionwindow,thepartialwordreceivedonSDIwillbe  
ignoredandtheSoftSpanconfigurationregisterwillnotbe  
updated. If exactly 24 SCKI rising edges are provided, the  
SoftSpan configuration register will be updated to match  
the received SoftSpan configuration word, S[23:0]. The  
one exception to this behavior occurs when S[23:0] is all  
zeros. In this case, the SoftSpan configuration register  
will not be updated, allowing applications to retain the  
current SoftSpan configuration state by idling SDI low. If  
more than24SCKI risingedges areprovided during a data  
transaction window, each complete 24-bit word received  
onSDIwillbeinterpretedasanewSoftSpanconfiguration  
word and applied to the SoftSpan configuration register  
as described above. Any partial words are ignored.  
After the opening of a new data transaction window at the  
falling edge of BUSY, the user supplies a 24-bit SoftSpan  
configuration word on SDI during the first 24 SCKI cycles.  
Thisnewwordoverwritestheinternalconfigurationregister  
contentsfollowingthe24thSCKIrisingedge.Theuserthen  
holds SDI low for the remainder of the data transaction  
windowcausingtheregistertoretainitscontentsregardless  
of the number of additional SCKI cycles applied. SoftSpan  
settings may be retained across multiple conversions by  
holding SDI low for the entire data transaction window,  
regardless of the number of SCKI cycles applied.  
Serial LVDS I/O Mode  
In LVDS I/O mode, information is transmitted using posi-  
+
tive and negative signal pairs (LVDS /LVDS ) with bits  
+
differentially encoded as (LVDS LVDS ). These signals  
are typically routed using differential transmission lines  
Typically, applications will update the SoftSpan configura-  
tion register in the manner shown in Figures 16 and 17.  
Rev A  
33  
For more information www.analog.com  
LTC2358-16  
APPLICATIONS INFORMATION  
with 100Ω characteristic impedance. Logical 1’s and 0’s  
are nominally represented by differential +350mV and  
−350mV,respectively.Forclarity,allLVDStimingdiagrams  
and interface discussions adopt the logical rather than  
physical convention.  
version on the falling edge of BUSY. In the recommended  
use case, the data transaction should be completed with  
a minimum t  
time of 20ns prior to the start of the  
QUIET  
next conversion, as shown in Figure 19. New SoftSpan  
configuration words are only accepted within this recom-  
mended data transaction window, but SoftSpan changes  
take effect immediately with no additional analog input  
settling time required before starting the next conversion.  
It is still possible to read conversion data after starting the  
nextconversion,butthiswilldegradeconversionaccuracy  
and therefore is not recommended.  
As shown in Figure 19, in LVDS I/O mode the serial data  
busconsistsofaserialclockdifferentialinput, SCKI, serial  
data differential input, SDI, serial clock differential output,  
SCKO, and serial data differential output, SDO. Communi-  
cation with the LTC2358-16 across this bus occurs during  
predefined data transaction windows. Within a window,  
the device accepts 24-bit SoftSpan configuration words  
for the next conversion on SDI and outputs 24-bit packets  
containing conversion results and channel configuration  
information from the previous conversion on SDO. New  
data transaction windows open 10ms after powering up  
or resetting the LTC2358-16, and at the end of each con-  
Just prior to the falling edge of BUSY and the opening of  
a new data transaction window, SDO is updated with the  
latestconversionresultsfromanaloginputchannel0.Both  
rising and falling edges on SCKI serially clock conversion  
resultsandanaloginputchannelconfigurationinformation  
out on SDO. SCKI is also echoed on SCKO, skew-matched  
CS ꢓ ꢔꢋ ꢓ ꢊ  
ꢀAꢐꢔꢟꢘ ꢍ  
ꢀAꢐꢔꢟꢘ ꢍ ꢢ ꢃ  
ꢌꢝꢌ  
ꢌꢍꢎꢩ  
ꢌꢍꢎ  
ꢏꢌꢐꢑꢀꢒ  
ꢌꢍꢎꢟ  
ꢛꢜꢀꢝ  
ꢏꢌꢐꢑꢀꢒ  
ꢌꢑꢍꢎ  
Aꢌꢚ  
ꢛꢜꢀꢝꢟꢩ  
Rꢘꢌꢑꢐꢐꢘꢍꢋꢘꢋ ꢋAꢗA ꢗRAꢍꢀAꢌꢗꢠꢑꢍ ꢡꢠꢍꢋꢑꢡ  
ꢚꢜꢠꢘꢗ  
ꢀꢌꢞꢠ  
ꢀꢌꢞꢠꢩ  
ꢀꢌꢞꢠ  
ꢋꢀꢒ  
ꢉ ꢃꢊ ꢃꢃ ꢃꢁ ꢃꢂ ꢃꢄ ꢃꢅ ꢃꢆ ꢃꢇ ꢃꢈ ꢃꢉ ꢁꢊ ꢁꢃ ꢁꢁ ꢁꢂ ꢁꢄ ꢁꢅ ꢁꢆ ꢃꢈꢅ ꢃꢈꢆ ꢃꢈꢇ ꢃꢈꢈ ꢃꢈꢉ ꢃꢉꢊ ꢃꢉꢃ ꢃꢉꢁ  
ꢩꢀꢋꢠꢀꢌꢞꢠ  
ꢀꢌꢞꢠꢟ  
ꢀꢀꢋꢠꢀꢌꢞꢠ  
ꢩꢀꢋꢠꢀꢌꢞꢠ  
ꢀꢀꢋꢠꢀꢌꢞꢠ  
ꢀꢋꢠ  
ꢋꢀꢒ  
ꢋꢑꢍARꢘ  
ꢀꢁꢂ ꢁꢁ ꢀꢁꢃ ꢀꢁꢊ ꢀꢃꢉ ꢀꢃꢈ ꢀꢃꢇ ꢀꢃꢆ ꢀꢃꢅ ꢀꢃꢄ ꢀꢃꢂ ꢀꢃꢁ ꢀꢃꢃ ꢀꢃꢊ  ꢀꢈ ꢀꢇ ꢀꢆ ꢀꢅ ꢀꢄ ꢀꢂ ꢀꢁ ꢀꢃ ꢀꢊ  
ꢀꢣꢤꢙꢀꢥꢦꢧ ꢌꢑꢍꢕꢠꢨꢜRAꢗꢠꢑꢍ ꢡꢑRꢋ ꢕꢑR ꢌꢑꢍꢎꢘRꢀꢠꢑꢍ ꢍ ꢢ ꢃ  
ꢋꢀꢋꢑꢛꢜꢀꢝꢟ  
ꢀꢞꢘꢡ  
ꢩꢀꢋꢑꢀꢌꢞꢠ  
ꢀꢌꢞꢑ  
ꢋꢀꢒ  
ꢋꢀꢋꢑꢀꢌꢞꢠ  
ꢀꢋꢑ  
ꢋꢀꢒ  
ꢋꢑꢍARꢘ  
ꢋꢃꢅ  
ꢋꢃꢄ ꢋꢃꢂ ꢋꢃꢁ ꢋꢃꢃ ꢋꢃꢊ  ꢋꢈ ꢋꢇ ꢋꢆ ꢋꢅ ꢋꢄ ꢋꢂ ꢋꢁ ꢋꢃ ꢋꢊ  
ꢌꢑꢍꢎꢘRꢀꢠꢑꢍ Rꢘꢀꢜꢗ  
ꢌꢁ ꢌꢃ ꢌꢊ ꢀꢁ ꢀꢀꢃ ꢀꢀꢊ ꢋꢃꢅ ꢋꢃꢄ ꢋꢃꢂ  
ꢌꢩAꢍꢍꢘꢟ ꢠꢋ ꢀꢣꢤꢙꢀꢥꢦꢧ  
ꢌꢁ ꢌꢃ ꢌꢊ ꢀꢁ ꢀꢀꢃ ꢀꢀꢊ ꢋꢃꢅ  
ꢌꢑꢍꢎꢘRꢀꢠꢑꢍ  
Rꢘꢀꢜꢗ  
ꢌꢩAꢍꢍꢘꢟ ꢠꢋ ꢀꢣꢤꢙꢀꢥꢦꢧ  
ꢌꢩAꢍꢍꢘꢟ ꢊ  
ꢁꢄꢪꢛꢠꢗ ꢔAꢌꢞꢘꢗ  
ꢌꢑꢍꢎꢘRꢀꢠꢑꢍ ꢍ  
ꢌꢩAꢍꢍꢘꢟ ꢃ  
ꢌꢩAꢍꢍꢘꢟ ꢇ  
ꢌꢩAꢍꢍꢘꢟ ꢊ  
ꢁꢄꢪꢛꢠꢗ ꢔAꢌꢞꢘꢗ  
ꢌꢑꢍꢎꢘRꢀꢠꢑꢍ ꢍ  
ꢁꢂꢅꢈꢃꢆ ꢕꢃꢉ  
ꢁꢄꢪꢛꢠꢗ ꢔAꢌꢞꢘꢗ  
ꢁꢄꢪꢛꢠꢗ ꢔAꢌꢞꢘꢗ  
ꢌꢑꢍꢎꢘRꢀꢠꢑꢍ ꢍ ꢌꢑꢍꢎꢘRꢀꢠꢑꢍ ꢍ  
Figure 19. Serial LVDS I/O Mode  
Rev A  
34  
For more information www.analog.com  
LTC2358-16  
APPLICATIONS INFORMATION  
tothedataonSDO.Wheneverpossible,itisrecommended  
that rising and falling edges of SCKO be used to capture  
DDR serial output data on SDO, as this will yield the best  
robustness to delay variations over supply and tempera-  
ture. SCKI rising and falling edges also latch SoftSpan  
configuration words provided on SDI, which are used to  
programtheinternal24-bitSoftSpanconfigurationregister.  
See the section Programming the SoftSpan Configuration  
Register in LVDS I/O Mode for further details. As shown in  
Figure 20, the LVDS bus is enabled when CS is low and is  
disabled and Hi-Z when CS is high, allowing the bus to be  
shared across multiple devices. Due to the high speeds  
involved in LVDS signaling, LVDS bus sharing must be  
carefullyconsidered.Transmissionlinelimitationsimposed  
by the shared bus may limit the maximum achievable bus  
clock speed. LVDS inputs are internally terminated with a  
100Ω differential resistor when CS is low, while outputs  
must be differentially terminated with a 100Ω resistor at  
the receiver (FPGA). SCKI must idle in the low state in  
LVDS I/O mode, including when transitioning CS.  
ThedataonSDOaregroupedinto24-bitpacketsconsisting  
of a 16-bit conversion result followed by two zeros, 3-bit  
analog channel ID, and 3-bit SoftSpan code, all presented  
MSBfirst.AssuggestedinFigures19and20,SDOoutputs  
these packets for all analog input channels in a sequential,  
circularmanner.Forexample,thefirst24-bitpacketoutput  
on SDO corresponds to analog input channel 0, followed  
by the packets for channels 1 through 7. The data output  
on SDO then wraps back to channel 0, and this pattern  
repeats indefinitely.  
ꢆꢇ ꢈ ꢉ  
ꢎꢏꢄꢐ  
ꢀꢁꢂꢃꢄꢅ  
CS  
ꢀꢁꢂꢃꢄꢅ  
ꢍꢊ  
ꢇꢔꢄ  
ꢄꢁꢑꢔ  
ꢇꢄꢅ  
ꢇꢃꢊARꢍ  
ꢇꢃꢊARꢍ  
ꢄꢇꢔ  
ꢇꢄꢅ  
ꢊꢍꢠ ꢄꢡꢢꢣꢄꢤꢥꢦ ꢁꢃꢊꢛꢔꢧꢏRAꢌꢔꢃꢊ ꢠꢃRꢇ  
ꢀꢃꢓꢍRꢠRꢔꢌꢍꢄ ꢔꢊꢌꢍRꢊAꢒ ꢁꢃꢊꢛꢔꢧ RꢍꢧꢔꢄꢌꢍRꢅ  
ꢌꢠꢃ AꢒꢒꢞꢟꢍRꢃ ꢠꢃRꢇꢄ Aꢊꢇ ꢃꢊꢍ ꢆARꢌꢔAꢒ ꢠꢃRꢇ  
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ꢇꢃꢊARꢍ  
ꢇꢃꢊARꢍ  
ꢜꢝꢞꢟ  
ꢜꢝꢞꢟ  
ꢄꢁꢑꢃ  
ꢇꢄꢅ  
ꢜꢝꢞꢟ  
ꢜꢝꢞꢟ  
ꢕꢖꢗꢘꢙꢚ ꢛꢕꢉ  
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ꢀꢆARꢌꢔAꢒꢅ  
ꢄꢇꢃ  
ꢇꢄꢅ  
ꢁꢜAꢊꢊꢍꢒ ꢉ ꢆAꢁꢑꢍꢌ  
ꢁꢜAꢊꢊꢍꢒ ꢙ ꢆAꢁꢑꢍꢌ  
ꢁꢜAꢊꢊꢍꢒ ꢕ ꢆAꢁꢑꢍꢌ  
Figure 20. Internal SoftSpan Configuration Register Behavior. Serial LVDS Bus Response to CS  
Rev A  
35  
For more information www.analog.com  
LTC2358-16  
APPLICATIONS INFORMATION  
Serial LVDS Output Data Capture  
If fewer than 24 SCKI edges (rising plus falling) are  
provided during a data transaction window, the partial  
word received on SDI will be ignored and the SoftSpan  
configuration register will not be updated. If exactly 24  
SCKI edges are provided, the SoftSpan configuration  
register will be updated to match the received SoftSpan  
configuration word, S[23:0]. The one exception to this  
behavior occurs when S[23:0] is all zeros. In this case,  
the SoftSpan configuration register will not be updated,  
allowing applications to retain the current SoftSpan con-  
figuration state by idling SDI low. If more than 24 SCKI  
edgesareprovidedduringadatatransactionwindow,each  
complete 24-bit word received on SDI will be interpreted  
as a new SoftSpan configuration word and applied to the  
SoftSpan configuration register as described above. Any  
partial words are ignored.  
As shown in Table 2, full 200ksps per channel throughput  
can be achieved with a 180MHz SCKI frequency by captur-  
ing eight packets (96 SCKI cycles total) of DDR data from  
SDO. The LTC2358-16 supports LVDS SCKI frequencies  
up to 250MHz.  
Programming the SoftSpan Configuration Register in  
LVDS I/O Mode  
The internal 24-bit SoftSpan configuration register con-  
trols the SoftSpan range for all analog input channels of  
the LTC2358-16. The default state of this register after  
power-up or resetting the device is all ones, configuring  
each channel to convert in SoftSpan 7, the 2.5 • V  
REFBUF  
range (see Table 1a). The state of this register may be  
modifiedbyprovidinganew24-bitSoftSpanconfiguration  
word on SDI during the data transaction window shown  
in Figure 19. New SoftSpan configuration words are only  
accepted within this recommended data transaction win-  
dow, but SoftSpan changes take effect immediately with  
no additional analog input settling time required before  
starting the next conversion. Setting a channel’s SoftSpan  
code to SS[2:0] = 000 immediately disables the channel,  
Typically, applications will update the SoftSpan configura-  
tion register in the manner shown in Figures 19 and 20.  
After the opening of a new data transaction window at  
the falling edge of BUSY, the user supplies a 24-bit DDR  
SoftSpan configuration word on SDI during the first 12  
SCKI cycles. This new word overwrites the internal con-  
th  
figuration register contents following the 12 SCKI falling  
edge. The user then holds SDI low for the remainder of  
the data transaction window causing the register to retain  
its contents regardless of the number of additional SCKI  
cycles applied. SoftSpan settings may be retained across  
multiple conversions by holding SDI low for the entire  
data transaction window, regardless of the number of  
SCKI cycles applied  
resultinginacorrespondingreductionint  
onthenext  
CONV  
conversion.Similarly,enablingapreviouslydisabledchan-  
nelrequiresnoadditionalanaloginputsettlingtimebefore  
starting the next conversion. The mapping between the  
serial SoftSpan configuration word, the internal SoftSpan  
configuration register, and each channel’s 3-bit SoftSpan  
code is illustrated in Figure 18.  
Rev A  
36  
For more information www.analog.com  
LTC2358-16  
BOARD LAYOUT  
To obtain the best performance from the LTC2358-16, a  
four-layer printed circuit board (PCB) is recommended.  
Layout for the PCB should ensure the digital and analog  
signal lines are separated as much as possible. In particu-  
lar, care should be taken not to run any digital clocks or  
signals alongside analog signals or underneath the ADC.  
Also minimize the length of the REFBUF to GND (Pin 20)  
bypass capacitor return loop, and avoid routing CNV near  
signals which could potentially disturb its rising edge.  
Supply bypass capacitors should be placed as close as  
possible to the supply pins. Low impedance common re-  
turns for these bypass capacitors are essential to the low  
noise operation of the ADC. A single solid ground plane  
is recommended for this purpose. When possible, screen  
the analog input traces using ground.  
Reference Design  
For a detailed look at the reference design for this con-  
verter, including schematics and PCB layout, please refer  
to DC2365, the evaluation kit for the LTC2358-16.  
Rev A  
37  
For more information www.analog.com  
LTC2358-16  
PACKAGE DESCRIPTION  
Please refer to http://www.linear.com/product/LTC2358-16#packaging for the most recent package drawings.  
LX Package  
48-Lead Plastic LQFP (7mm × 7mm)  
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ꢐꢏꢐꢇ Rꢊꢅ  
ꢑꢏꢇꢇ ꢒꢓꢔ  
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ꢇꢏꢐꢇ ꢒꢓꢔ  
ꢑꢏꢇꢇ ꢒꢓꢔ  
ꢎꢏꢇꢇ ꢒꢓꢔ  
ꢐꢏꢐꢇ Rꢊꢅ  
ꢎꢏꢈꢐ ꢍ ꢎꢏꢕꢐ  
ꢇꢏꢕꢇ ꢍ ꢇꢏꢉꢇ  
A
A
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ꢇꢏꢈꢎ ꢍ ꢇꢏꢕꢎ  
ꢇꢏꢇꢐ ꢍ ꢇꢏꢈꢐ  
ꢇꢏꢂꢐ ꢍ ꢇꢏꢎꢐ  
ꢓꢊꢔꢜꢠꢛꢚ A ꢍ A  
e ꢉ  
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ꢀꢁꢂꢃ ꢀꢄꢅꢆ ꢇꢈꢈꢉ Rꢊꢋ A  
ꢜRAꢦ ꢆꢠꢚ ꢈ  
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Rev A  
38  
For more information www.analog.com  
LTC2358-16  
REVISION HISTORY  
REV  
DATE  
DESCRIPTION  
PAGE NUMBER  
A
05/18 Updated max limits for analog input leakage  
1, 3  
Rev A  
Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog  
Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications  
subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices.  
39  
LTC2358-16  
TYPICAL APPLICATION  
Amplify Differential Signals with Gain of 10  
Over a Wide Common Mode Range with Buffered Analog Inputs  
INTERNAL HI-Z BUFFERS  
ARBITRARY  
31V  
ALLOW OPTIONAL  
+
31V  
kΩ PASSIVE FILTERS  
LTC2057HV  
GAIN = 10  
LTC2057HV  
+
IN  
24V  
3.65k  
0.1µF  
BUFFERED  
ANALOG  
INPUTS  
2.49k  
V
+
CC  
COMMON MODE  
INPUT RANGE  
IN0  
IN0  
549Ω  
2.49k  
2.2nF  
LTC2358-16  
3.65k  
DIFFERENTIAL MODE  
INPUT RANGE: 500ꢀV  
+
V
REFBUF  
47µF  
REFIN  
EE  
0V  
BW = 10kHz  
IN  
0.1µF  
0.1µF  
–7V  
–7V  
235816 TA02  
ONLY CHANNEL 0 SHOWN FOR CLARITY  
RELATED PARTS  
PART NUMBER  
ADCs  
DESCRIPTION  
COMMENTS  
LTC2358-18  
18-Bit, 200ksps/Ch, Buffered 8-Channel  
10.24V Buffered SoftSpan Inputs with 30V Common Mode Range,  
P-P  
Simultaneous Sampling, 3.5LSB INL, Serial ADC 96.4dB SNR, Serial CMOS and LVDS I/O, 7mm × 7mm LQFP-48 Package  
LTC2348-18/LTC2348-16 18-/16-Bit, 200ksps/Ch, 8-Channel Simultaneous 10.24V SoftSpan Inputs with Wide Common Mode Range, 97dB/94dB  
Sampling, 3LSB/ 1LSB INL, Serial ADC  
SNR, Serial CMOS and LVDS I/O, 7mm × 7mm LQFP-48 Package  
LTC2335-18/LTC2335-16 18-/16-Bit, 1Msps, 8-Channel Multiplexed,  
3LSB/ 1LSB INL, Serial ADC  
10.24V SoftSpan Inputs with Wide Common Mode Range, 97dB/94dB  
SNR, Serial CMOS and LVDS I/O, 7mm × 7mm LQFP-48 Package  
LTC2345-18/LTC2345-16 18-/16-Bit, 200ksps/Ch, 8-Channel Simultaneous 4.096V SoftSpan Inputs with Wide Common Mode Range, 92dB/91dB  
Sampling, 5LSB/ 1.25LSB INL, Serial ADC  
SNR, Serial CMOS and LVDS I/O, 7mm × 7mm QFN-48 Package  
LTC2378-20/LTC2377-20/ 20-Bit, 1Msps/500ksps/250ksps,  
2.5V Supply, 5V Fully Differential Input, 104dB SNR, MSOP-16 and  
4mm × 3mm DFN-16 Packages  
LTC2376-20  
0.5ppm INL Serial, Low Power ADC  
LTC2338-18/LTC2337-18/ 18-Bit, 1Msps/500ksps/250ksps, Serial,  
LTC2336-18 Low Power ADC  
LTC2328-18/LTC2327-18/ 18-Bit, 1Msps/500ksps/250ksps, Serial,  
LTC2326-18 Low Power ADC  
LTC2373-18/LTC2372-18 18-Bit, 1Msps/500ksps, 8-Channel, Serial ADC  
5V Supply, 10.24V Fully Differential Input, 100dB SNR, MSOP-16 Package  
5V Supply, 10.24V Pseudo-Differential Input, 95dB SNR,  
MSOP-16 Package  
5V Supply, 8 Channel Multiplexed, Configurable Input Range, 100dB SNR,  
DGC, 5mm × 5mm QFN-32 Package  
LTC2379-18/LTC2378-18/ 18-Bit,1.6Msps/1Msps/500ksps/250ksps, Serial, 2.5V Supply, Differential Input, 101.2dB SNR, 5V Input Range, DGC, Pin  
LTC2377-18/LTC2376-18 Low Power ADC Compatible Family in MSOP-16 and 4mm × 3mm DFN-16 Packages  
LTC2380-16/LTC2378-16/ 16-Bit, 2Msps/1Msps/500ksps/250ksps, Serial, 2.5V Supply, Differential Input, 96.2dB SNR, 5V Input Range, DGC, Pin  
LTC2377-16/LTC2376-16 Low Power ADC  
LTC2387-18/LTC2387-16 18-/16-Bit, 15Msps SAR ADC  
Compatible Family in MSOP-16 and 4mm × 3mm DFN-16 Packages  
5V Supply, Differential Input, 93.8dB SNR, 5mm × 5mm QFN Package  
LTC1859/LTC1858/  
LTC1857  
16-/14-/12-Bit, 8-Channel, 100ksps, Serial ADC  
10V, SoftSpan, Single-Ended or Differential Inputs, Single 5V Supply,  
SSOP-28 Package  
DACs  
LTC2756/LTC2757  
18-Bit, Serial/Parallel I  
SoftSpan DAC  
1LSB INL/DNL, Software-Selectable Ranges, SSOP-28/7mm × 7mm  
LQFP-48 Package  
OUT  
LTC2668  
16-Channel 16-/12-Bit 10V V  
SoftSpan DACs 4LSB INL, Precision Reference 10ppm/°C Max, 6mm × 6mm QFN-40 Package  
OUT  
References  
LTC6655  
Precision Low Drift Low Noise Buffered Reference 5V/2.5V/2.048V/1.25V, 2ppm/°C, 0.25ppm Peak-to-Peak Noise, MSOP-8  
Package  
LT6657  
Precision Low Drift Low Noise Buffered Reference 5V/3V/2.5V, 1.5ppm/°C, 0.5ppm Peak-to-Peak Noise, MSOP-8 Package  
Amplifiers  
LTC2057/LTC2057HV  
LT6020  
High Voltage, Low Noise Zero-Drift Op Amp  
Dual, Micropower, 5V/µs, Rail-to-Rail Op Amp  
Maximum Input Offset: 4.5µV, Supply Voltage Range: 4.75V to 60V  
Maximum Input Offset: 30µV, Maximum Supply Current: 100µA/Amplifier  
LT1354/LT1355/LT1356  
Single/Dual/Quad 1mA, 12MHz, 400V/µs Op Amp Good DC Precision, Stable with All Capacitive Loads  
Rev A  
D16870-0-5/18(A)  
www.analog.com  
40  
© ANALOG DEVICES, INC. 2016-2018  

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