LT1789CS8-1-TR [Linear]
Micropower, Single Supply Rail-to-Rail Output Instrumentation Amplifiers; 微功耗，单电源轨至轨输出仪表放大器
| 型号： | LT1789CS8-1-TR |
| 厂家： | 
Linear |
| 描述： | Micropower, Single Supply Rail-to-Rail Output Instrumentation Amplifiers |
| 文件： | 总24页 (文件大小：326K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
LT1789-1/LT1789-10
Micropower,
Single Supply Rail-to-Rail
Output Instrumentation Amplifiers
FEATURES
DESCRIPTION
The LT®1789-1/LT1789-10 are micropower, precision
instrumentation amplifiers that are optimized for single
n
Micropower: 95μA Supply Current Max
n
Low Input Offset Voltage: 100μV Max
n
Low Input Offset Voltage Drift: 0.5μV/°C Max
Single Gain Set Resistor:
supply operation from 2.2V to 36V. The quiescent current
is 95μA max, the inputs common mode to ground and the
output swings within 110mV of ground. The gain is set
with a single external resistor for a gain range of 1 to 1000
for the LT1789-1 and 10 to 1000 for the LT1789-10.
n
G = 1 to 1000 (LT1789-1)
G = 10 to 1000 (LT1789-10)
–
n
n
n
n
n
n
n
n
n
Inputs Common Mode to V
Wide Supply Range: 2.2V to 36V Total Supply
CMRR at G = 10: 96dB Min
The high accuracy of the LT1789-1 (40ppm maximum non-
linearity and 0.25% max gain error) is unmatched by other
micropower instrumentation amplifiers. The LT1789-10
maximizesboththeinputcommonmoderangeanddynamic
outputrangewhenanamplificationof10orgreaterisrequired,
allowingprecisesignalprocessingwhereotherinstrumenta-
tion amplifiers fail to operate. The LT1789-1/LT1789-10 are
laser trimmed for very low input offset voltage, low input
offset voltage drift, high CMRR and high PSRR. The output
canhandlecapacitiveloadsupto400pF(LT1789-1), 1000pF
(LT1789-10) in any gain configuration while the inputs are
ESD protected up to 10kV (human body).
Gain Error: G = 10, 0.25% Max
Gain Nonlinearity: G = 10, 40ppm Max
Input Bias Current: 40nA Max
PSRR at G = 10: 100dB Min
1kHz Voltage Noise: 48nV/√Hz
0.1Hz to 10Hz Noise: 1.5μV
P-P
APPLICATIONS
n
Portable Instrumentation
n
Bridge Amplifiers
n
Strain Gauge Amplifiers
Thermocouple Amplifiers
Differential to Single-Ended Converters
Medical Instrumentation
The LT1789-1/LT1789-10 are offered in the 8-pin SO
package, requiring significantly less PC board area than
discrete multi op amp and resistor designs.
n
n
n
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
TYPICAL APPLICATION
0.5A to 4A Voltage Controlled Current Source
C1
4700pF
V
S
C3
V
S
120Ω
R1
8k
0.1μF
90.9k
–
+
2
3
7
R3
100Ω
TIP127*
V
IN
6
R2
10k
LT1636
*ENSURE ADEQUATE POWER
DISSIPATION CAPABILITY AT
HIGHER VOLTAGES,
V
5
S
4
7
3
8
+
–
3
4
CURRENTS AND DUTY CYCLES
R4
10k
1
2
6
R
*
I
LT1789-1
4
SENSE
0.1Ω
REF
5
LOAD
R
C2
3300pF
1
2
V
S
= 3.3V TO 32V
V
IN
I
=
LOAD
R
• 10
SENSE
= 1A PER VOLT AS SHOWN
*
LOAD
RISE TIME ≈ 250μs, 10% TO 90%,
1A TO 2A OUTPUT STEP INTO 0.25Ω LOAD
1789 TA01
1789fc
1
LT1789-1/LT1789-10
ABSOLUTE MAXIMUM RATINGS
PIN CONFIGURATION
(Note 1)
+
–
TOP VIEW
Supply Voltage (V to V )..........................................36V
Input Differential Voltage ..........................................36V
Input Current (Note 3)......................................... 20mA
Output Short-Circuit Duration.......................... Indefinite
Operating Temperature Range .................–40°C to 85°C
Specified Temperature Range (Note 4)
R
1
2
3
4
8
7
6
5
R
G
G
–IN
+IN
+V
S
OUT
REF
–V
S
S8 PACKAGE
8-LEAD PLASTIC SO
= 150°C, θ = 190°C/W
LT1789C-1, LT1789C-10.......................–40°C to 85°C
LT1789I-1, LT1789I-10 ........................–40°C to 85°C
Storage Temperature Range .................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec)...................300°C
T
JMAX
JA
ORDER INFORMATION
LEAD FREE FINISH
LT1789CS8-1#PBF
LT1789IS8-1#PBF
LT1789CS8-10#PBF
LT1789IS8-10#PBF
LEAD BASED FINISH
LT1789CS8-1
TAPE AND REEL
PART MARKING
17891
PACKAGE DESCRIPTION
8-Lead Plastic SO
8-Lead Plastic SO
8-Lead Plastic SO
8-Lead Plastic SO
PACKAGE DESCRIPTION
8-Lead Plastic SO
8-Lead Plastic SO
8-Lead Plastic SO
8-Lead Plastic SO
TEMPERATURE RANGE
LT1789CS8-1#TRPBF
LT1789IS8-1#TRPBF
LT1789CS8-10#TRPBF
LT1789IS8-10#TRPBF
TAPE AND REEL
–40°C to 85°C
–40°C to 85°C
–40°C to 85°C
–40°C to 85°C
TEMPERATURE RANGE
–40°C to 85°C
–40°C to 85°C
–40°C to 85°C
–40°C to 85°C
1789I1
178910
789I10
PART MARKING
17891
LT1789CS8-1#TR
LT1789IS8-1#TR
LT1789IS8-1
1789I1
LT1789CS8-10
LT1789CS8-10#TR
LT1789IS8-10#TR
178910
LT1789IS8-10
789I10
Consult LTC Marketing for parts specified with wider operating temperature ranges.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/
3V AND 5V ELECTRICAL CHARACTERISTICS VS = 3V, 0V; VS = 5V, 0V; RL = 20k, VCM = VREF = half
supply, TA = 25°C, unless otherwise noted.
LT1789-1
TYP
LT1789-10
TYP
SYMBOL PARAMETER
CONDITIONS
LT1789-1, G = 1 + (200k/R )
MIN
MAX
MIN
MAX UNITS
G
Gain Range
1
1000
G
LT1789-10, G = 10 • [1+ (200k/R )]
10
1000
%
G
Gain Error (Note 6)
G = 1, V = 0.1V to (+V ) – 1V
0.02
0.20
O
S
LT1789-1, V = 0.1V to (+V ) – 0.3V
O
S
LT1789-10, V = 0.2V to (+V ) – 0.3V
O
S
G = 10 (Note 2)
0.06
0.06
0.13
0.25
0.27
0.01
0.09
0.16
0.25
0.30
%
%
%
G = 100 (Note 2)
G = 1000 (Note 2)
Gain Nonlinearity (Note 6)
G = 1, V = 0.1V to (+V ) – 1V
35
100
ppm
O
S
LT1789-1, V = 0.1V to (+V ) – 0.3V
O
S
LT1789-10, V = 0.2V to 4.7V, V = 5V
O
S
(Note 8)
G = 10
G = 100
G = 1000
12
18
90
40
75
15
20
100
100
100
ppm
ppm
ppm
1789fc
2
LT1789-1/LT1789-10
3V AND 5V ELECTRICAL CHARACTERISTICS VS = 3V, 0V; VS = 5V, 0V; RL = 20k, VCM = VREF = half
supply, TA = 25°C, unless otherwise noted.
LT1789-1
TYP
LT1789-10
TYP
SYMBOL PARAMETER
CONDITIONS
= V + V /G
MIN
MAX
MIN
MAX UNITS
V
V
V
Total Input Referred Offset Voltage
Input Offset Voltage
V
OST
OST
OSI
OSO
G = 1000
15
150
0.2
19
100
750
4
20
650
0.2
19
160
3000
4
μV
μV
nA
nA
OSI
Output Offset Voltage
Input Offset Current
G = 1 (LT1789-1), G =10 (LT1789-10)
OSO
I
I
(Note 6)
(Note 6)
OS
Input Bias Current
40
40
B
e
n
Input Noise Voltage,
RTI (Referred to Input)
G = 1, f = 0.1Hz to 10Hz
5.0
1.5
1.0
μV
μV
μV
O
P-P
P-P
P-P
G = 10
4.6
1.1
G = 100, 1000
2
2
Total RTI Noise = √e + (e /G)
ni
no
e
e
Input Noise Voltage Density, RTI f = 1kHz (Note 7)
48
330
16
85
52
270
16
90
nV/√Hz
nV/√Hz
ni
O
Output Noise Voltage Density, RTI f = 1kHz (Note 3)
no
O
i
n
Input Noise Current
Input Noise Current Density
Input Resistance
f = 0.1Hz to 10Hz
pA
P-P
O
f = 1kHz
O
62
62
fA/√Hz
R
V
IN
= 0V to (+V ) – 1V (Note 6)
0.75
0
1.6
0.75
0
1.6
GΩ
IN
S
C
Input Capacitance
Differential
Common Mode
1.6
1.6
1.6
1.6
pF
pF
IN
V
Input Voltage Range
+V – 1
S
+V – 1.2
S
V
CM
CMRR
Common Mode Rejection Ratio
1k Source Imbalance (Note 6)
LT1789-1,V = 0V to (+V ) – 1V
CM
S
LT1789-10, V = 0V to (+V ) – 1.2V
CM
S
79
96
100
100
88
dB
dB
dB
dB
G = 1
106
114
114
88
98
98
105
113
113
G = 10
G = 100
G = 1000
PSRR
Power Supply Rejection Ratio
V = 2.5V to 12.5V, V = V = 1V
S
CM
REF
90
100
113
116
116
dB
dB
dB
dB
G = 1
100
102
102
94
102
102
109
120
120
G = 10
G = 100
G = 1000
Minimum Supply Voltage
Supply Current
2.2
67
54
2.5
95
2.2
67
62
2.5
95
V
μA
mV
V
I
(Note 7)
S
V
V
Output Voltage Swing LOW
Output Voltage Swing HIGH
Short-Circuit Current
(Note 7)
100
110
OL
(Note 7)
+V – 0.3 +V – 0.19
+V – 0.3 +V – 0.19
S S
OH
S
S
I
Short to GND
Short to +V
2.2
8.5
2.2
8.5
mA
mA
SC
S
60
30
3
kHz
kHz
kHz
kHz
BW
Bandwidth
G = 1
25
12
1.5
G = 10
G = 100
G = 1000
0.2
SR
Slew Rate
G = 10, V
4V Step
= 0.5V to 4.5V
0.023
240
0.062
190
V/μs
μs
OUT
Settling Time to 0.01%
Reference Input Resistance
Reference Input Current
Reference Gain to Output
R
REFIN
220
220
kΩ
μA
I
V
REF
= 0V
2.7
2.7
REFIN
AV
REF
1
0.0001
1
0.0001
1789fc
3
LT1789-1/LT1789-10
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the temperature range of
0°C ≤ TA ≤ 70°C. VS = 3V, 0V; VS = 5V, 0V; RL = 20k, VREF = half supply, unless otherwise noted. (Note 4)
LT1789-1
TYP
LT1789-10
TYP
SYMBOL PARAMETER
Gain Error (Note 6)
CONDITIONS
G = 1, V = 0.3V to (+V ) – 1V
MIN
MAX
MIN
MAX
UNITS
l
0.25
%
O
S
V = 0.3V to (+V ) – 0.5V
O
S
l
l
G = 10 (Note 2)
0.53
0.55
0.30
0.53
%
%
G = 100 (Note 2)
l
Gain Nonlinearity (Note 6)
G = 1, V = 0.3V to (+V ) – 1V
185
ppm
O
S
LT1789-1, V = 0.3V to (+V ) – 0.5V
O
S
LT1789-10, V = 0.3V to 4.7V, V = 5V
O
S
(Note 8)
G = 10
G = 100
l
l
90
120
130
130
ppm
ppm
l
G/T
Gain vs Temperature
G < 1000 (Notes 2, 3)
Total Input Referred Offset Voltage V = V + V /G
OST
5
3
50
5
3
50
ppm/°C
V
V
V
V
V
V
V
OST
OSI
OSO
l
l
l
l
l
l
l
l
l
l
l
190
10
Input Offset Voltage
G = 1000
150
10
µV
µV
OSI
Input Offset Voltage Hysteresis
Output Offset Voltage
(Notes 3, 5)
OSIH
OSO
OSOH
G = 1 (LT1789-1), G = 10 (LT1789-10)
950
100
0.5
4
3700
900
0.7
µV
Output Offset Voltage Hysteresis (Notes 3, 5)
50
0.2
1.5
300
0.3
7
µV
/T
Input Offset Voltage Drift (RTI)
(Note 3)
(Note 3)
(Note 6)
µV/°C
µV/°C
nA
OSI
/T Output Offset Voltage Drift
Input Offset Current
20
OSO
I
I
I
4.5
4.5
OS
/T
OS
B
Input Offset Current Drift
Input Bias Current
3
3
pA/°C
nA
(Note 6)
45
45
pA/°C
I /T
B
Input Bias Current Drift
Input Voltage Range
50
50
V
CM
0.2
(+V ) – 1
0.2
(+V ) – 1.5
V
S
S
CMRR
Common Mode Rejection Ratio
1k Source Imbalance (Note 6)
LT1789-1, V = 0.2V to (+V ) – 1V
CM
S
LT1789-10, V = 0.2V to (+V ) – 1.5V
CM
S
l
l
l
G = 1
77
94
98
dB
dB
dB
G = 10
85
96
G = 100, 1000
V = 2.5V to 12.5V, V = V = 1V
PSRR
Power Supply Rejection Ratio
S
CM
REF
l
l
l
G = 1
88
98
100
dB
dB
dB
G = 10
G = 100, 1000
92
100
l
l
l
l
Minimum Supply Voltage
Supply Current
2.5
115
110
2.5
115
120
V
µA
mV
V
(Note 7)
(Note 7)
(Note 7)
I
S
V
V
Output Voltage Swing LOW
Output Voltage Swing HIGH
OL
+V – 0.38
S
+V – 0.38
S
OH
1789fc
4
LT1789-1/LT1789-10
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the temperature range of
–40°C ≤ TA ≤ 85°C. VS = 3V, 0V; VS = 5V, 0V; RL = 20k, VREF = half supply, unless otherwise noted. (Note 4)
LT1789-1
TYP
LT1789-10
TYP
SYMBOL PARAMETER
Gain Error (Note 6)
CONDITIONS
G = 1, V = 0.3V to (+V ) – 1V
MIN
MAX
MIN
MAX
UNITS
l
0.30
%
O
S
V = 0.3V to (+V ) – 0.5V
O
S
l
l
G = 10 (Note 2)
0.57
0.59
0.35
0.62
%
%
G = 100 (Note 2)
l
Gain Nonlinearity (Note 6)
G = 1, V = 0.3V to (+V ) – 1V
250
ppm
O
S
LT1789-1, V = 0.3V to (+V ) – 0.5V
O
S
LT1789-10, V = 0.3V to 4.7V, V = 5V
O
S
(Note 8)
G = 10
G = 100
l
l
105
160
150
170
ppm
ppm
l
G/T
Gain vs Temperature
G < 1000 (Notes 2, 3)
Total Input Referred Offset Voltage V = V + V /G
OST
5
3
50
5
3
50
ppm/°C
V
V
V
V
V
V
V
OST
OSI
OSO
l
l
l
l
l
l
l
l
l
l
l
205
10
Input Offset Voltage
G = 1000
175
10
µV
µV
OSI
Input Offset Voltage Hysteresis
Output Offset Voltage
(Notes 3, 5)
OSIH
OSO
OSOH
G = 1 (LT1789-1), G = 10 (LT1789-10)
1050
100
0.5
4
4000
900
0.7
20
µV
Output Offset Voltage Hysteresis (Notes 3, 5)
50
0.2
1.5
300
0.3
7
µV
/T
Input Offset Voltage Drift (RTI)
(Note 3)
(Note 3)
(Note 6)
µV/°C
µV/°C
nA
OSI
/T Output Offset Voltage Drift
Input Offset Current
OSO
I
I
I
5
5
OS
/T
OS
B
Input Offset Current Drift
Input Bias Current
3
3
pA/°C
nA
(Note 6)
50
50
pA/°C
I /T
B
Input Bias Current Drift
Input Voltage Range
50
50
V
CM
0.2
+V – 1
S
0.2
+V – 1.5
S
V
CMRR
Common Mode Rejection Ratio
1k Source Imbalance (Note 6)
LT1789-1, V = 0.2V to (+V ) – 1V
CM
S
LT1789-10, V = 0.2V to (+V ) – 1.5V
CM
S
l
l
l
G = 1
75
92
96
dB
dB
dB
G = 10
84
94
G = 100, 1000
V = 2.5V to 12.5V, V = V = 1V
PSRR
Power Supply Rejection Ratio
S
CM
REF
l
l
l
G = 1
86
96
98
dB
dB
dB
G = 10
G = 100, 1000
90
98
l
l
l
l
Minimum Supply Voltage
Supply Current
2.5
125
120
2.5
125
130
V
µA
mV
V
(Note 7)
(Note 7)
(Note 7)
I
S
V
V
Output Voltage Swing LOW
Output Voltage Swing HIGH
OL
+V – 0.40
S
+V – 0.40
S
OH
1789fc
5
LT1789-1/LT1789-10
ELECTRICAL CHARACTERISTICS
VS = 15V, RL = 20k, VCM = VOUT = 0V, TA = 25°C, unless otherwise noted.
LT1789-1
TYP
LT1789-10
TYP
SYMBOL PARAMETER
CONDITIONS
LT1789-1, G = 1 + (200k/R )
MIN
MAX
MIN
MAX UNITS
G
Gain Range
1
1000
G
LT1789-10, G = 10 • [1+ (200k/R )]
10
1000
G
Gain Error
V = 10V
O
G = 1
0.01
0.04
0.04
0.07
0.10
0.15
0.15
0.20
%
G = 10 (Note 2)
G = 100 (Note 2)
G = 1000 (Note 2)
0.01
0.03
0.03
0.15
0.20
0.25
%
%
%
Gain Nonlinearity
V = 10V
O
G = 1
8
1
20
10
ppm
ppm
ppm
ppm
G = 10
G = 100
G = 1000
5
5
25
40
40
160
6
20
20
100
V
V
V
Total Input Referred Offset Voltage
Input Offset Voltage
V
= V + V /G
OST
OST OSI OSO
G = 1000
G = 1 (LT1789-1), G =10 (LT1789-10)
30
0.2
0.2
17
235
1
30
0.6
0.2
17
295
3.3
4
μV
mV
nA
OSI
Output Offset Voltage
Input Offset Current
OSO
I
I
4
OS
Input Bias Current
40
40
nA
B
e
n
Input Noise Voltage, RTI
f = 0.1Hz to 10Hz
O
G = 1
5.0
1.5
1.0
μV
μV
μV
P-P
P-P
P-P
G = 10
G = 100, 1000
4.6
1.1
2
2
Total RTI Noise = √e + (e /G)
ni
no
e
e
Input Noise Voltage Density, RTI f = 1kHz
49
330
19
90
53
270
19
95 nV/√Hz
nV/√Hz
ni
O
Output Noise Voltage Density, RTI f = 1kHz
no
O
i
n
Input Noise Current
Input Noise Current Density
Input Resistance
f = 0.1Hz to 10Hz
pA
P-P
O
f = 1kHz
O
62
62
fA/√Hz
R
2
4.7
2
4.7
GΩ
IN
C
IN
Input Capacitance
Differential
Common Mode
20
17
20
17
pF
pF
V
CM
Input Voltage Range
–15
–14
–15
–14
V
CMRR
Common Mode Rejection Ratio
1k Source Imbalance, V = –15V to 14V
CM
80
98
102
89
108
117
dB
dB
dB
G = 1
93
102
108
123
G = 10
G = 100, 1000
PSRR
Power Supply Rejection Ratio
LT1789-1 V = 1.25V to 16V
S
94
104
102
107
118
121
dB
dB
dB
LT1789-10 V = 1.50V to 16V
S
100
106
115
123
G = 1
G = 10
G = 100, 1000
Minimum Supply Voltage
Supply Current
1.25
130
1.50
130
V
μA
V
I
85
85
S
V
Output Voltage Swing
Short-Circuit Current
14.5
14.7
14.5
14.7
O
I
SC
Short to –V
Short to +V
2.2
8.5
2.2
8.5
mA
mA
S
S
1789fc
6
LT1789-1/LT1789-10
ELECTRICAL CHARACTERISTICS
VS = 15V, RL = 20k, VCM = VOUT = 0V, TA = 25°C, unless otherwise noted.
LT1789-1
LT1789-10
TYP
SYMBOL PARAMETER
CONDITIONS
MIN
TYP
MAX
MIN
MAX UNITS
60
30
3
kHz
kHz
kHz
kHz
BW
Bandwidth
G = 1
25
12
1.5
G = 10
G = 100
G = 1000
0.2
SR
Slew Rate
V
=
10V
0.012
0.026
460
0.028
0.066
270
220
2.7
V/μs
μs
OUT
Settling Time to 0.01%
Reference Input Resistance
Reference Input Current
Reference Gain to Output
10V Step
R
REFIN
220
kΩ
μA
I
V
= 0V
2.7
REFIN
REF
AV
REF
1
0.0001
1 0.0001
The l denotes the specifications which apply over the temperature range of 0°C ≤ TA ≤ 70°C. VS = 15V, RL = 20k, VCM = VREF = 0V,
unless otherwise noted. (Note 4)
LT1789-1
TYP
LT1789-10
TYP
SYMBOL PARAMETER
CONDITIONS
MIN
MAX
MIN
MAX
UNITS
Gain Error
V = 10V
O
G = 1
l
l
l
l
0.15
0.38
0.38
0.43
%
%
%
%
G = 10 (Note 2)
G = 100 (Note 2)
G = 1000 (Note 2)
0.20
0.43
0.48
Gain Nonlinearity
V = 10V
O
G = 1
l
l
l
l
25
15
ppm
ppm
ppm
ppm
G = 10
G = 100
G = 1000
45
45
180
25
120
l
G/T
Gain vs Temperature
G < 1000 (Notes 2, 3)
5
8
50
5
8
50
ppm/°C
V
V
V
V
V
V
V
Total Input Referred Offset Voltage V
= V + V /G
OST OSI OSO
OST
l
l
l
l
l
l
l
l
l
l
l
325
30
Input Offset Voltage
G = 1000
(Notes 3, 5)
G = 1
285
30
µV
µV
OSI
Input Offset Voltage Hysteresis
Output Offset Voltage
OSIH
OSO
OSOH
1.2
120
0.7
5
4
mV
Output Offset Voltage Hysteresis (Notes 3, 5)
50
0.2
1.5
400
0.3
8
1000
0.8
22
µV
/T
Input Offset Voltage Drift (RTI)
(Note 3)
(Note 3)
µV/°C
µV/°C
nA
OSI
/T Output Offset Voltage Drift
Input Offset Current
OSO
I
I
I
4.5
4.5
OS
/T
OS
Input Offset Current Drift
Input Bias Current
2
2
pA/°C
nA
45
14
45
14
B
pA/°C
I /T
B
Input Bias Current Drift
Input Voltage Range
35
35
V
CM
G = 1, Other Input Grounded
1k Source Imbalance,
–14.8
–14.8
V
CMRR
Common Mode Rejection Ratio
V
= –14.8V to 14V
CM
l
l
l
78
96
100
dB
dB
dB
G = 1
91
100
G = 10
G = 100, 1000
1789fc
7
LT1789-1/LT1789-10
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the temperature range of
0°C ≤ TA ≤ 70°C. VS = 15V, RL = 20k, VCM = VREF = 0V, unless otherwise noted. (Note 4)
LT1789-1
TYP
LT1789-10
TYP
SYMBOL PARAMETER
PSRR Power Supply Rejection Ratio
CONDITIONS
MIN
MAX
MIN
MAX
UNITS
LT1789-1, V = 1.25V to 16V
S
LT1789-10, V = 1.50V to 16V
S
l
l
l
92
102
104
dB
dB
dB
G = 1
G = 10
G = 100, 1000
98
104
l
l
l
l
Minimum Supply Voltage
Supply Current
1.25
150
1.50
150
V
µA
I
S
V
Output Voltage Swing
Slew Rate
14.25
0.010
14.25
0.026
V
O
SR
V
=
10V
V/µs
OUT
The l denotes the specifications which apply over the temperature range of –40°C ≤ TA ≤ 85°C. VS = 15V, RL = 20k, VCM = VREF = 0V,
unless otherwise noted. (Note 4)
LT1789-1
TYP
LT1789-10
TYP
SYMBOL PARAMETER
CONDITIONS
MIN
MAX
MIN
MAX
UNITS
Gain Error
V = 10V
O
G = 1
l
l
l
l
0.20
0.57
0.57
0.62
%
%
%
%
G = 10 (Note 2)
G = 100 (Note 2)
G = 1000 (Note 2)
0.25
0.62
0.67
Gain Nonlinearity
V = 10V
O
G = 1
l
l
l
l
30
20
ppm
ppm
ppm
ppm
G = 10
G = 100
G = 1000
50
50
200
30
130
l
G/T
Gain vs Temperature
G < 1000 (Notes 2, 3)
5
8
50
5
8
50
ppm/°C
V
V
V
V
V
V
V
Total Input Referred Offset Voltage V
= V + V /G
OST OSI OSO
OST
l
l
l
l
l
l
l
l
l
l
l
340
30
Input Offset Voltage
G = 1000
(Notes 3, 5)
G = 1
305
30
1.3
120
0.7
5
µV
µV
OSI
Input Offset Voltage Hysteresis
Output Offset Voltage
OSIH
OSO
OSOH
4.2
1000
0.8
22
mV
Output Offset Voltage Hysteresis (Notes 3, 5)
50
0.2
1.5
400
0.3
8
µV
/T
Input Offset Voltage Drift (RTI)
(Note 3)
(Note 3)
µV/°C
µV/°C
nA
OSI
/T Output Offset Voltage Drift
OSO
I
I
I
Input Offset Current
5
5
OS
/T
OS
B
Input Offset Current Drift
Input Bias Current
2
2
pA/°C
nA
50
14
50
14
pA/°C
I /T
B
Input Bias Current Drift
Input Voltage Range
35
35
V
CM
G = 1, Other Input Grounded
1k Source Imbalance,
–14.8
–14.8
V
CMRR
Common Mode Rejection Ratio
V
= –14.8V to 14V
CM
l
l
l
76
94
98
dB
dB
dB
G = 1
89
98
G = 10
G = 100, 1000
1789fc
8
LT1789-1/LT1789-10
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the temperature range of
–40°C ≤ TA ≤ 85°C. VS = 15V, RL = 20k, VCM = VREF = 0V, unless otherwise noted. (Note 4)
LT1789-1
TYP
LT1789-10
TYP
SYMBOL PARAMETER
PSRR Power Supply Rejection Ratio
CONDITIONS
MIN
MAX
MIN
MAX
UNITS
LT1789-1, V = 1.25V to 16V
S
LT1789-10, V = 1.50V to 16V
S
l
l
l
90
100
102
dB
dB
dB
G = 1
G = 10
G = 100, 1000
96
102
l
l
l
l
Minimum Supply Voltage
Supply Current
1.25
160
1.50
160
V
µA
I
S
V
Output Voltage Swing
Slew Rate
14.15
0.008
14.15
0.024
V
O
SR
V
=
10V
V/µs
OUT
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 5: Hysteresis in offset voltage is created by package stress that
differs depending on whether the IC was previously at a higher or lower
temperature. Offset voltage hysteresis is always measured at 25°C, but
the IC is cycled to 85°C I-grade (or 70°C C-grade) or –40°C I-grade
(0°C C-grade) before successive measurement. 60% of the parts will
pass the typical limit on the data sheet.
Note 2: Does not include the effect of the external gain resistor R .
G
Note 3: This parameter is not 100% tested.
Note 6: V = 5V limits are guaranteed by correlation to V = 3V and
S
S
Note 4: The LT1789C-1/ LT1789C-10 is guaranteed to meet specified
performance from 0°C to 70°C and is designed, characterized and
expected to meet these extended temperature limits, but is not tested at
–40°C and 85°C. The LT1789I-1/ LT1789I-10 is guaranteed to meet the
extended temperature limits.
V = 15V tests.
S
Note 7: V = 3V limits are guaranteed by correlation to V = 5V and
S
S
V = 15V tests.
S
Note 8: This parameter is not tested at V = 3V on the LT1789-10 due
S
to an increase in sensitivity to test system noise. Actual performance is
expected to be similar to performance at V = 5V.
S
TYPICAL PERFORMANCE CHARACTERISTICS (LT1789-1, LT1789-10)
Input Bias Current
vs Temperature
Input Bias Current
Supply Current vs Supply Voltage
vs Common Mode Input Voltage
–10
–12
–14
–16
–18
–20
–22
–24
–26
–28
–30
120
110
100
90
0
–5
V
V
= 5V, 0V
CM
–55°C
S
= 2.5V
125°C
125°C
25°C
85°C
80
–10
–15
–20
–25
25°C
70
60
–55°C
50
40
V
V
= 5V, 0V
REF
S
30
= 2.5V
20
–0.5 0 0.5
2.5 3
1 4.5 5
1.5 2 3.5 4
0
20
30 35
–50 –25
0
25
50
75 100 125
5
10 15
25
40
COMMON MODE INPUT VOLTAGE (V)
TOTAL SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
1789 G03
1789 G01
1789 G02
1789fc
9
LT1789-1/LT1789-10
TYPICAL PERFORMANCE CHARACTERISTICS (LT1789-1)
Output Voltage Swing
vs Load Current
Gain vs Frequency
Slew Rate vs Temperature
5.0
4.8
4.6
4.4
4.2
4.0
80
70
60
50
40
30
20
10
0
0.050
–55°C
V
V
= 5V, 0V
= 2.5V
V
V
= 5V, 0V
= 2.5V
S
REF
S
REF
0.045
0.040
125°C
SOURCE
G = 1000
G = 100
G = 10
G = 1
= 20k
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
R
L
25°C
0.035
0.030
0.025
0.020
0.015
RISING
V
V
= 5V, 0V
REF
S
= 2.5V
125°C
25°C
FALLING
G = 1
SINK
–55°C
–10
–20
0.010
0.001
0.01
0.1
1
10
–25
0
50
75 100 125
–50
25
100
1k
10k
100k
OUTPUT CURRENT (mA)
TEMPERATURE (°C)
FREQUENCY (Hz)
1789 G04
1789 G05
1789 G06
Common Mode Rejection Ratio
vs Frequency
Negative Power Supply Rejection
Ratio vs Frequency
Positive Power Supply Rejection
Ratio vs Frequency
120
110
100
140
120
100
80
140
120
100
80
V
V
= 5V, 0V
V
V
= 5V, 0V
V
V
= 5V, 0V
REF
S
S
S
= 2.5V
= 2.5V
= 2.5V
REF
REF
G = 100, 1000
G = 10
INPUT REFERRED
INPUT REFERRED
G = 1000
G = 10
G = 1
G = 100
G = 10
G = 100, 1000
G = 1
90
80
G = 1
60
60
70
60
40
40
20
20
50
40
0
0
10
100
1k
10k 20k
10
100
1k
10k 20k
10
100
1k
10k 20k
FREQUENCY (Hz)
FREQUENCY (Hz)
FREQUENCY (Hz)
1879 G07
1789 G08
1789 G09
Settling Time to 0.01% vs
Output Step
Output Impedance vs Frequency
Overshoot vs Capacitive Load
100
90
10
8
10k
1k
V
=
15V
V
V
= 5V, 0V
= 2.5V
V
V
V
= 5V, 0V
= 2.5V
OUT
S
S
REF
S
REF
R
= 20k
L
G = 1
= 100mV
P-P
6
80
70
4
2
60
50
100
10
0
40
30
20
10
0
–2
–4
–6
–8
–10
A
= 1
V
A
= 10
V
A
≥ 100
V
1
100
0
100
200
300
400
500
1
10
100
1000
1k
10k
100k
FREQUENCY (Hz)
SETTLING TIME (μs)
CAPACITIVE LOAD (pF)
1789 G11
1789 G12
1789 G10
1789fc
10
LT1789-1/LT1789-10
TYPICAL PERFORMANCE CHARACTERISTICS (LT1789-1)
Voltage Noise Density vs
Frequency
Current Noise Density vs
Frequency
1000
100
10
1000
100
10
V
V
= 5V, 0V
V
V
= 5V, 0V
REF
S
S
= 2.5V
= 2.5V
REF
INPUT REFERRED
G = 1
G = 10
R
S
G = 100, 1000
LT1789-1
10
1
10
100
1k
1
100
1k
FREQUENCY (Hz)
FREQUENCY (Hz)
1789 G13
1789 G14
0.1Hz to 10Hz Noise Voltage,
G = 1
0.1Hz to 10Hz Noise Voltage,
RTI, G = 1000
V
V
= 5V, 0V
= 2.5V
V
V
= 5V, 0V
= 2.5V
S
REF
S
REF
0
1
2
3
4
5
6
7
8
9
10
0
1
2
3
4
5
6
7
8
9 10
TIME (SEC)
TIME (SEC)
1789 G16
1789 G15
0.1Hz to 10Hz Noise Current
Turn-On Characteristics
1.5
0.5
V
V
= 5V, 0V
= 2.5V
V
V
V
= 5V, 0V
= 2.5V
S
REF
S
REF
CM
= 2.5V
G = 1000
= 25°C
T
A
–0.5
–1.5
0
1
2
3
4
5
6
7
8
9
10
0
10
20
30
40
TIME (SEC)
TIME (ms)
1789 G17
1789 G18
1789fc
11
LT1789-1/LT1789-10
TYPICAL PERFORMANCE CHARACTERISTICS (LT1789-10)
Output Voltage Swing
vs Load Current
Gain vs Frequency
Slew Rate vs Temperature
5.0
4.8
4.6
4.4
4.2
4.0
80
70
60
50
40
30
20
10
0
0.12
0.11
0.10
0.09
0.08
0.07
0.06
0.05
0.04
V
V
= 5V, 0V
= 2.5V
–55°C
S
REF
125°C
SOURCE
G = 1000
G = 100
G = 10
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
RISING
25°C
V
V
= 5V, 0V
REF
S
= 2.5V
125°C
FALLING
25°C
SINK
–55°C
–10
–20
0.001
0.01
0.1
1
10
–25
0
25
50
75
125
100
1k
10k
100k
–50
100
OUTPUT CURRENT (mA)
FREQUENCY (Hz)
TEMPERATURE (°C)
1789 G22
1789 G21
1789 G23
Common Mode Rejection Ratio
vs Frequency
Negative Power Supply Rejection
Ratio vs Frequency
Positive Power Supply Rejection
Ratio vs Frequency
120
110
100
90
140
120
100
80
140
120
100
80
V
V
= 5V, 0V
REF
V
V
= 5V, 0V
= 2.5V
V
V
= 5V, 0V
= 2.5V
S
S
REF
S
REF
G = 100, 1000
= 2.5V
G = 100, 1000
G = 10
G = 1000
INPUT REFERRED
INPUT REFERRED
G = 10
G = 100
G = 10
80
60
60
70
40
40
60
20
20
50
40
0
0
10
100
1k
10k 20k
10
100
1k
10k 20k
10
100
1k
10k 20k
FREQUENCY (Hz)
FREQUENCY (Hz)
FREQUENCY (Hz)
1789 G24
1789 G25
1789 G26
Settling Time to 0.01% vs
Output Step
Output Impedance vs Frequency
Overshoot vs Capacitive Load
100
90
10
8
10k
1k
V
=
15V
V
V
= 5V, 0V
= 2.5V
V
V
V
= 5V, 0V
= 2.5V
OUT
S
S
REF
S
REF
R
= 20k
L
G = 10
= 100mV
P-P
80
6
70
4
60
50
2
100
10
0
40
30
20
10
0
–2
–4
–6
–8
–10
G = 1000
G = 100
G = 10
1
100
10
100
CAPACITIVE LOAD (pF)
1000
0
100
200
300
400
500
1789 G29
1k
10k
100k
FREQUENCY (Hz)
SETTLING TIME (μs)
1789 G28
1789 G27
1789fc
12
LT1789-1/LT1789-10
TYPICAL PERFORMANCE CHARACTERISTICS (LT1789-10)
Voltage Noise Density vs
Frequency
Current Noise Density vs
Frequency
1000
100
10
1000
100
10
V
V
= 5V, 0V
V
V
= 5V, 0V
REF
S
S
= 2.5V
= 2.5V
REF
INPUT REFERRED
G = 10
G = 100
G = 1000
R
S
LT1789-10
1
10
100
1k
1
10
100
1k
FREQUENCY (Hz)
FREQUENCY (Hz)
1789 G30
1789 G31
0.1Hz to 10Hz Noise Voltage,
RTI, G = 10
0.1Hz to 10Hz Noise Voltage,
RTI, G = 1000
V
V
= 5V, 0V
REF
V
V
= 5V, 0V
REF
S
S
= 2.5V
= 2.5V
0
1
2
3
4
5
6
7
8
9
10
0
1
2
3
4
5
6
7
8
9
10
TIME (SEC)
TIME (SEC)
1789 G32
1789 G33
0.1Hz to 10Hz Noise Current
Turn-On Characteristics
1.5
0.5
V
V
= 5V, 0V
= 2.5V
V
V
V
= 5V, 0V
= 2.5V
S
REF
S
REF
CM
= 2.5V
G = 1000
= 25°C
T
A
–0.5
–1.5
0
1
2
3
4
5
6
7
8
9
10
0
10
20
30
40
TIME (SEC)
TIME (ms)
1789 G34
1789 G59
1789fc
13
LT1789-1/LT1789-10
TYPICAL PERFORMANCE CHARACTERISTICS (LT1789-1)
Large-Signal Transient Response
G = 1, 10, 100
Large-Signal Transient Response
G = 1000
5V/DIV
5V/DIV
1789 G39
1789 G38
V
=
15V
2ms/DIV
V
R
C
=
15V
500μs/DIV
S
L
S
L
L
R
C
= 20k
= 20k
= 50pF
= 50pF
L
Small-Signal Transient Response
G = 1
Small-Signal Transient Response
G = 10
20mV/DIV
20mV/DIV
1789 G41
1789 G40
V
V
= 5V, 0V
= 2.5V
100μs/DIV
V
V
= 5V, 0V
= 2.5V
100μs/DIV
S
REF
L
S
REF
L
R
C
= 20k
R
C
= 20k
= 50pF
= 50pF
L
L
Small-Signal Transient Response
G = 100
Small-Signal Transient Response
G = 1000
20mV/DIV
20mV/DIV
1789 G43
1789 G42
V
V
= 5V, 0V
= 2.5V
2ms/DIV
V
V
= 5V, 0V
= 2.5V
200μs/DIV
S
REF
L
S
REF
L
R
C
= 20k
R
C
= 20k
= 50pF
= 50pF
L
L
1789fc
14
LT1789-1/LT1789-10
TYPICAL PERFORMANCE CHARACTERISTICS (LT1789-10)
Large-Signal Transient Response
G = 10, 100
Large-Signal Transient Response
G = 1000
Small-Signal Transient Response
G = 10
20mV/DIV
5V/DIV
5V/DIV
1789 G46
1789 G44
1789 G45
V
V
= 5V, 0V
= 2.5V
100μs/DIV
V
=
15V
500μs/DIV
V
=
15V
500μs/DIV
S
REF
R
S
L
S
L
R
C
= 20k
R
C
= 20k
= 20k
= 50pF
= 50pF
L
L
L
L
C
= 50pF
Small-Signal Transient Response
G = 100
Small-Signal Transient Response
G = 1000
20mV/DIV
20mV/DIV
1789 G47
1789 G48
V
V
= 5V, 0V
= 2.5V
200μs/DIV
V
V
= 5V, 0V
= 2.5V
2ms/DIV
S
REF
L
S
REF
L
R
C
= 20k
R
C
= 20k
= 50pF
= 50pF
L
L
1789fc
15
LT1789-1/LT1789-10
TYPICAL PERFORMANCE CHARACTERISTICS (LT1789-1)
Valid Output Voltage vs Input
Common Mode Voltage
VS = 15V
Valid Output Voltage vs Input
Common Mode Voltage
VS = 2.5V
Valid Output Voltage vs Input
Common Mode Voltage
VS = 1.5V
15
10
5
3.0
2.5
1.5
1.0
T
= 25°C
T
= 25°C
A
A
T = 25°C
A
A
V
= 10
G ≥ 2
G = 1
A
= 1
= 2
V
2.0
A
= 1
V
A
V
A = 10
V
1.5
A
= 2
V
0.5
1.0
0.5
0
0
0
–0.5
–1.0
–1.5
–2.0
–2.5
–5
–10
–15
–0.5
–1.0
–1.5
–15
–5
0
5
10
15
–10
–2.5
–1.5
–0.5
0.5
1.5
2.5
–1.5
–0.5
0
0.5
1.0
1.5
–1.0
INPUT COMMON MODE VOLTAGE (V)
INPUT COMMON MODE VOLTAGE (V)
INPUT COMMON MODE VOLTAGE (V)
15V
2.5V
1.5V
+
+
+
+
+
+
V
V
V
V /2
D
V /2
D
V /2
D
V
V
V
LT1789-1
LT1789-1
LT1789-1
OUT
OUT
OUT
V /2
D
V /2
D
V /2
D
REF
REF
REF
20K
20K
20K
V
CM
V
V
CM
CM
–
–
–
V
–
–
–
V
V
1789 G49
–15V
–2.5V
–1.5V
1789 G50
1789 G51
Valid Output Voltage vs Input
Common Mode Voltage
VS = 5V
Valid Output Voltage vs Input
Common Mode Voltage
VS = 3V
3
5
4
3
2
1
0
T
A
= 25°C
T
= 25°C
A
2
1
0
G = 1
G = 1
G = 2
G = 2
G = 10
G = 10
1
2
3
4
5
0
0.5
1.5
2.0
2.5
3.0
0
1.0
INPUT COMMON MODE VOLTAGE (V)
INPUT COMMON MODE VOLTAGE (V)
5V
3V
+
+
+
+
V
V
V /2
D
V /2
D
V
V
LT1789-1
LT1789-1
OUT
OUT
V /2
D
V /2
D
REF
REF
20K
20K
V
CM
V
CM
–
–
V
–
–
V
1789 G52
1789 G53
1789fc
16
LT1789-1/LT1789-10
TYPICAL PERFORMANCE CHARACTERISTICS (LT1789-10)
Valid Output Voltage vs Input
Common Mode Voltage
VS = 15V
Valid Output Voltage vs Input
Common Mode Voltage
VS = 2.5V
Valid Output Voltage vs Input
Common Mode Voltage
VS = 1.5V
15
10
5
2.5
2.0
1.5
1.0
G = 10
T
= 25°C
T = 25°C
A
A
A
= 10
V
T
= 25°C
A
A
= 10
V
G = 100
A
= 100
V
1.5
A
= 100
V
1.0
0.5
0.5
0
0
0
–0.5
–1.0
–1.5
–2.0
–2.5
–5
–10
–15
–0.5
–1.0
–1.5
–15
–5
0
5
10
15
0
–0.5
–10
–2.5
–1.5
0.5
1.5
2.5
–1.5
–0.5
0
0.5
1.0
1.5
–1.0
INPUT COMMON MODE VOLTAGE (V)
INPUT COMMON MODE VOLTAGE (V)
INPUT COMMON MODE VOLTAGE (V)
15V
2.5V
1.5V
+
+
+
+
+
+
V
V
V
V /2
D
V /2
D
V /2
D
V
V
V
LT1789-10
LT1789-10
LT1789-10
OUT
OUT
OUT
V /2
D
V /2
D
V /2
D
REF
REF
REF
20K
20K
20K
V
CM
V
V
CM
CM
–
–
–
–
–
–
V
V
V
–15V
–2.5V
–1.5V
1789 G54
1789 G55
1789 G56
Valid Output Voltage vs Input
Common Mode Voltage
VS = 5V
Valid Output Voltage vs Input
Common Mode Voltage
VS = 3V
5
4
3
2
1
0
3
2
1
0
T
= 25°C
A
T = 25°C
A
G = 10
G = 10
G = 100
G = 100
1
2
3
4
5
0
0.5
1.5
2.0
2.5
3.0
0
1.0
INPUT COMMON MODE VOLTAGE (V)
INPUT COMMON MODE VOLTAGE (V)
3V
5V
+
+
+
+
V
V
V /2
D
V /2
D
V
V
LT1789-10
LT1789-10
OUT
OUT
V /2
D
V /2
D
REF
REF
20K
20K
V
CM
V
CM
–
–
–
–
V
V
1789 G57
1789 G58
1789fc
17
LT1789-1/LT1789-10
BLOCK DIAGRAM
+
+
V
V
100k
+
V
5.7k
+IN
3
–
+
R1
R2
R
1
8
G
110k/10k* 110k/100k*
A1
5
REF
–
+
–
+
V
V
V
V
V
B
–
V
+
A3
R
G
100k
+
–
V
5.7k
–IN
2
–
+
R3
R4
110k/10k* 110k/100k*
A2
6
7
OUT
–
–
V
V
+
V
–
V
B
V
*LT1789-1/LT1789-10
–
4
V
1789 F01
Figure 1. Block Diagram
APPLICATIONS INFORMATION
Setting the Gain
Input and Output Offset Voltage
The gain of the LT1789-1 and LT1789-10 is set by the
The offset voltage of the LT1789-1/LT1789-10 has two
components: the output offset and the input offset. The
total offset voltage referred to the input (RTI) is found by
dividingtheoutputoffsetbytheprogrammedgain(G)and
adding it to the input offset. At high gains the input offset
voltage dominates, whereas at low gains the output offset
voltage dominates. The total offset voltage is:
value of resistor R , applied across pins 1 and 8. For the
G
LT1789-1, the gain G will be:
G = 1+ 200k/R
G
and R can be calculated from the desired gain by
G
R = 200k/(G – 1)
G
To t a l i n p u t o f f s e t v o l t a g e ( R T I )
= input offset + (output offset/G)
For the LT1789-10, the gain G will be
G =10 • (1 + 200k/R )
G
To t a l o u t p u t o f f s e t v o l t a g e ( RT O )
= (input offset • G) + output offset
and R can be calculated from the desired gain by
G
R = 200k/(0.1 • G – 1)
G
For the lowest achievable gain, R may be set to infinity
G
by leaving Pins 1 and 8 open.
1789fc
18
LT1789-1/LT1789-10
APPLICATIONS INFORMATION
Reference Terminal
Input Bias Current Return Path
The low input bias current of the LT1789-1/LT1789-10
(19nA) and the high input impedance (1.6GΩ) allow the
use of high impedance sources without introducing sig-
nificant offset voltage errors, even when the full common
mode range is required. However, a path must be provided
for the input bias currents of both inputs when a purely
differential signal is being amplified. Without this path the
inputs will float high and exceed the input common mode
range of the LT1789-1/LT1789-10, resulting in a saturated
inputstage.Figure3showsthreeexamplesofaninputbias
current path. The first example is of a purely differential
signal source with a 10kΩ input current path to ground.
Since the impedance of the signal source is low, only one
resistor is needed. Two matching resistors are needed for
higher impedance signal sources as shown in the second
example. Balancing the input impedance improves both
common mode rejection and DC offset. The need for input
resistors is eliminated if a center tap is present as shown
in the third example.
The output voltage of the LT1789-1/LT1789-10 (Pin 6)
is referenced to the voltage on the reference terminal
(Pin 5). Resistance in series with the REF pin must be
minimized for best common mode rejection. For example,
a 22Ω resistance from the REF pin to ground will not
only increase the gain error by 0.02% but will lower the
CMRR to 80dB.
Output Offset Trimming
The LT1789-1/LT1789-10 is laser trimmed for low offset
voltage so that no external offset trimming is required for
most applications. In the event that the offset needs to be
adjusted,thecircuitinFigure2isanexampleofanoptional
offset adjust circuit. The op amp buffer provides a low
impedance to the REF pin where resistance must be kept
to a minimum for best CMRR and lowest gain error.
–
2
+
V
OUTPUT
6
–IN
1
8
3
R
G
LT1789-1/-10
REF
–
2
3
10mV
+
+IN
5
1
100Ω
10k
LT1880
+
10mV
ADJUSTMENT RANGE
100Ω
–10mV
–
V
1789 F02
Figure 2. Optional Trimming of Output Offset Voltage
–
+
–
–
+
MICROPHONE,
LT1789-1/
LT1789-1/
LT1789-10
LT1789-1/
LT1789-10
R
HYDROPHONE,
ETC
R
R
G
THERMOCOUPLE
G
G
LT1789-10
+
200k
200k
10k
CENTER-TAP PROVIDES
BIAS CURRENT RETURN
1789 F03
Figure 3. Providing an Input Common Mode Current Path
1789fc
19
LT1789-1/LT1789-10
APPLICATIONS INFORMATION
Output Voltage vs Input Common Mode Voltage
The LT1789-10 is less susceptible to this limiting factor
because the gain is taken in the output stage.
All instrumentation amplifiers have limiting factors that
can cause an output to be invalid (the output is not equal
to the input differential voltage multiplied by the gain)
even though the output appears to be operating in a linear
region. Limiting factors such as input voltage range and
output swing can be easily measured, however, there are
also internal nodes that can limit. These internal nodes
cannot be measured externally and can lead to erroneous
output readings.
3) The voltage on the inputs to the output amplifier A3
can be determined by the following formula:
V A3 = (V
IN
A1 – V )(R2/(R1 + R2))
REF
OUT
The input voltage range of A3 has the same input limits as
the LT1789-1. This limiting factor is more prevalent with
singlesupplies,whereboththereferencevoltageandinput
+
common mode voltage are near V . This is also more of
a concern with the LT1789-10 because the ratio of R1:R2
is 1:10 instead of 1:1.
To ensure a valid output for a given input common mode
voltage and input differential voltage, the following four
limiting factors must be taken into consideration (refer to
the block diagram):
4) The output voltage swing limits are also found in the
electrical tables.
TheOutputVoltagevsInputCommonModeVoltagetypical
performance curves show the regions of operation for the
three supply voltages specified.
1) The input voltage ranges of the input amplifiers A1 and
A2.
2) The output swings of the input amplifiers A1 and A2
(internal nodes).
Single Supply Operation
3) The input voltage range of the output amplifier A3
(internal node).
There are usually two types of input signals that need
to be processed; differential signals, like the output of a
bridge or single ended signals, such as the output from
a thermistor. Both signals require special consideration
when operating with a single supply.
4) The output swing of the output amplifier A3.
These limits can be determined using the relationships
below.
When processing differential signals , REF (Pin 5) must
be brought above the negative supply (Pin 4) to allow the
outputtoprocessboththepositiveandnegativegoinginput
signal. The maximum output operating range is obtained
by setting the voltage on the REF pin to half supply. This
must be done with a low impedance source to minimize
CMRR and gain errors.
1) The input voltage range limits can be found in the
electrical tables.
2) The output voltages of the input amplifiers A1 and A2
can be found by the following formulas:
V
V
A1 = (V /2)(G)(R1/R2) + V + 0.6V
D CM
OUT
OUT
A2 = (–V /2)(G)(R1/R2) + V + 0.6V
D
CM
For single ended input signals, the REF pin can be at the
same potential as the negative supply provided the output
oftheinstrumentationamplifierremainsinsidethespecified
operatingrange.Thismaximizestheoutputrange,however
the smallest input signal that can be processed is limited
by the output swing to the negative supply.
Where V is the input differential voltage and V is the
D
CM
input common mode voltage.
The typical output swing limits for A1 and A2 can be found
in the Output Swing vs Load Current typical performance
curve, using R1 + R2 as the load resistance.
This limitation usually becomes dominant when gain is
taken in the input stage and the common mode input
voltage is close to either supply rail.
1789fc
20
LT1789-1/LT1789-10
TYPICAL APPLICATIONS
Single Supply Positive Integrator
V
S
3
V
+
IN
7
V
S
R1
10k
8
6
3
2
LT1789-1
REF
+
–
1
2
1
+
V
LT1636
4
5
OUT
C1
100μF
R2
10Ω
–
4
RESET
1789 TA02
V
= 2.7V TO 32V
S
TIME CONSTANT = (R1)(C1) = 1 SECOND AS SHOWN
Avalanche Photo Diode Module Bias Current Monitor
FOR OPTIONAL “ZERO CURRENT” FEEDBACK TO
APD BIAS REGULATOR, SEE APPENDIX A, APPLICATION NOTE 92
1k*
1%
APD
HIGH VOLTAGE
BIAS INPUT
V
= 20V TO 90V
OUT
TO APD
1μF
100V
1μF
100V
100k*
100k*
Q1
1N4690
5.6V
1M*
0.2μF
5V
5V
6
–
1μF
+
–
20k
2
A1
OUTPUT
0V TO 1V =
0mA TO 1mA
S2
A2
LT1006
LT1789-1
+
10k
1μF
30k
5
0.2μF
Q2
MPSA42
20k*
–3.5V
1M*
–3.5V
20k
13
200k*
18
12
14
S1
–3.5V TO
AMPLIFIERS
5V
22μF
5V
3
S3
15
* = 0.1% METAL FILM RESISTOR
22μF
+
1μF 100V = TECATE CMC100105MX1825
CIRCLED NUMBERS = LTC1043 PIN NUMBER
#
= 1N4148
16
17
4
= TP0610L
0.056μF
5V
†
FOR MORE INFORMATION REFER TO APPLICATION NOTE 92
1789 TA05
1789fc
21
LT1789-1/LT1789-10
PACKAGE DESCRIPTION
S8 Package
8-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610)
.189 – .197
(4.801 – 5.004)
.045 .005
NOTE 3
.050 BSC
7
5
8
6
.245
MIN
.160 .005
.150 – .157
(3.810 – 3.988)
NOTE 3
.228 – .244
(5.791 – 6.197)
.030 .005
TYP
1
3
4
2
RECOMMENDED SOLDER PAD LAYOUT
.010 – .020
(0.254 – 0.508)
× 45°
.053 – .069
(1.346 – 1.752)
.004 – .010
(0.101 – 0.254)
.008 – .010
(0.203 – 0.254)
0°– 8° TYP
.016 – .050
(0.406 – 1.270)
.050
(1.270)
BSC
.014 – .019
(0.355 – 0.483)
TYP
NOTE:
INCHES
1. DIMENSIONS IN
(MILLIMETERS)
2. DRAWING NOT TO SCALE
3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)
SO8 0303
1789fc
22
LT1789-1/LT1789-10
REVISION HISTORY (Revision history begins at Rev C)
REV
DATE
DESCRIPTION
PAGE NUMBER
C
5/10
Updated Input Noise Current Density Spec
6
1789fc
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
23
LT1789-1/LT1789-10
TYPICAL APPLICATION
Voltage Controlled Current Source
3V TO 32V
3
V
IN
+
7
8
6
L
LT1789-1
R
G
REF
1
2
R1
1k
5
–
4
I
LOAD
I
L
= A • V /R1
V
IN
1789 TA03
200k
G
A
V
= 1 +
R
10°C to 40°C Thermometer
29.4k
1%
+
V
S
4
6
3
8
+
LT1790
–1.25
V
S
+
–
7
1
2
6
36.5k
0.5%
LT1789-10
4
1
2
V
= 2.5V AT 25°C + 50mV/°C
5
OUT
OVER 10°C TO 40°C
LINEARITY = 0.3°C
THERMISTOR
THERMOMETRICS
DC95G104V
100k
@ 25°C
866k
1%
ACCURACY = 1°C WORST CASE
TOLERANCE STACK-UP
56.2k
1%
+
V
= 4V TO 18V
S
1789 TA04
RELATED PARTS
PART NUMBER DESCRIPTION
COMMENTS
LTC1100
LT1101
LT1102
LT1167
Precision Chopper-Stabilized Instrumentation Amplifier
Best DC Accuracy
Precision, Micropower, Single Supply Instrumentation Amplifier
High Speed, JFET Instrumentation Amplifier
Fixed Gain of 10 or 100, I <105μA
S
Fixed Gain of 10 or 100, 30V/μs Slew Rate
Single Resistor Gain Programmable, Precision Instrumentation Amplifier Gain Error: 0.08% Max, Gain Nonlinearity: 10ppm Max,
60μV Max Input Offset Voltage, 90dB Min CMRR
LT1168
LTC®1418
Low Power, Single Resistor Programmable Instrumentation Amplifier
14-Bit, Low Power, 200ksps ADC with Serial and Parallel I/O
I
= 530μA Max
SUPPLY
Single Supply 5V or 5V Operation, 1.5LSB INL and
1LSB DNL Max
LT1460
LT1468
Precision Series Reference
Micropower; 2.5V, 5V, 10V Versions; High Precision
16-Bit Accurate Op Amp, Low Noise Fast Settling
16-Bit Accuracy at Low and High Frequencies, 90MHz GBW,
22V/μs, 900ns Settling
LTC1562
LTC1605
Active RC Filter
Lowpass, Bandpass, Highpass Responses; Low Noise,
Low Distortion, Four 2nd Order Filter Sections
16-Bit, 100ksps, Sampling ADC
Single 5V Supply, Bipolar Input Range: 10V,
Power Dissipation: 55mW Typ
1789fc
LT 0510 REV C • PRINTED IN USA
LinearTechnology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
24
●
●
© LINEAR TECHNOLOGY CORPORATION 2002
(408) 432-1900 FAX: (408) 434-0507 www.linear.com
相关型号：
LT1789CS8-10#TR
LT1789 - Micropower, Single Supply Rail-to-Rail Output Instrumentation Amplifier; Package: SO; Pins: 8; Temperature Range: 0°C to 70°C
Linear
LT1789IS8-1#TR
LT1789 - Micropower, Single Supply Rail-to-Rail Output Instrumentation Amplifier; Package: SO; Pins: 8; Temperature Range: -40°C to 85°C
Linear
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