DAC7644 [TI]
16-Bit, Quad Voltage Output DIGITAL-TO-ANALOG CONVERTER;型号: | DAC7644 |
厂家: | TEXAS INSTRUMENTS |
描述: | 16-Bit, Quad Voltage Output DIGITAL-TO-ANALOG CONVERTER |
文件: | 总25页 (文件大小:555K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
®
DAC7644
DAC7644
For most current data sheet and other product
information, visit www.burr-brown.com
16-Bit, Quad Voltage Output
DIGITAL-TO-ANALOG CONVERTER
DESCRIPTION
FEATURES
The DAC7644 is a 16-bit, quad voltage output digital-
to-analog converter with guaranteed 15-bit monotonic
performance over the specified temperature range. It
accepts 16-bit parallel input data, has double-buffered
DAC input logic (allowing simultaneous update of all
DACs), and provides a readback mode of the internal
input registers. Programmable asynchronous reset clears
all registers to a mid-scale code of 8000H or to a zero-
scale of 0000H. The DAC7644 can operate from a single
+5V supply or from +5V and –5V supplies.
● LOW POWER: 10mW
● UNIPOLAR OR BIPOLAR OPERATION
● SETTLING TIME: 10µs to 0.003%
● 15-BIT LINEARITY AND MONOTONICITY:
–40°C to +85°C
● PROGRAMMABLE RESET TO MID-SCALE
OR ZERO-SCALE
● DATA READBACK
● DOUBLE-BUFFERED DATA INPUTS
Low power and small size per DAC make the DAC7644
ideal for automatic test equipment, DAC-per-pin pro-
grammers, data acquisition systems, and closed-loop
servo-control. The DAC7644 is available in a 48-lead
SSOP package and offers guaranteed specifications
over the –40°C to +85°C temperature range.
APPLICATIONS
● PROCESS CONTROL
● CLOSED-LOOP SERVO-CONTROL
● MOTOR CONTROL
● DATA ACQUISITION SYSTEMS
● DAC-PER-PIN PROGRAMMERS
VREF
L
VREF
H
AB Sense
AB Sense
VREFL AB VREFH AB
VDD
VSS
VCC
DAC7644
16
I/O
Buffer
Input
Register A
DAC
Register A
DATA I/O
DAC A
VOUT
A
A
VOUT
Sense
Sense
Sense
Sense
Input
Register B
DAC
Register B
DAC B
DAC C
DAC D
VOUT
B
B
VOUT
A1
A0
Input
Register C
DAC
Register C
Control
Logic
VOUT
C
C
CS
R/W
VOUT
Input
Register D
DAC
Register D
VOUT
D
D
VOUT
VREFL CD VREFH CD
VREF
CD Sense
L
VREF
CD Sense
H
AGND DGND
RST
RSTSEL LOADDACS
International Airport Industrial Park
•
Mailing Address: PO Box 11400, Tucson, AZ 85734
•
Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706
FAX: (520) 889-1510
•
Tel: (520) 746-1111
Twx: 910-952-1111
•
Internet: http://www.burr-brown.com/
•
Cable: BBRCORP Telex: 066-6491
•
•
•
Immediate Product Info: (800) 548-6132
© 1999 Burr-Brown Corporation
PDS-1535B
Printedin U.S.A. November, 1999
SBAS121
SPECIFICATIONS (Dual Supply)
At TA = TMIN to TMAX, VDD = VCC = +5V, VSS = –5V, VREFH = +2.5V, and VREFL = –2.5V, unless otherwise noted.
DAC7644E
DAC7644EB
TYP
PARAMETER
CONDITIONS
MIN
TYP
MAX
MIN
MAX
UNITS
ACCURACY
Linearity Error
Linearity Match
±3
±4
±2
±4
±3
±2
±2
±1
±3
±2
LSB
LSB
LSB
Bits
mV
ppm/°C
mV
ppm/°C
mV
mV
ppm/V
Differential Linearity Error
Monotonicity, TMIN to TMAX
Bipolar Zero Error
Bipolar Zero Error Drift
Full-Scale Error
Full-Scale Error Drift
Bipolar Zero Matching
Full Scale Matching
Power Supply Rejection Ratio (PSRR)
14
15
±1
5
±1
5
±1
±1
10
±2
10
±2
10
±2
✻
✻
✻
✻
✻
✻
✻
✻
Channel-to-Channel Matching
Channel-to-Channel Matching
At Full Scale
±1
±1
✻
±2
±2
✻
±2
100
ANALOG OUTPUT
Voltage Output
Output Current
Maximum Load Capacitance
Short-Circuit Current
Short-Circuit Duration
VREF = –2.5V, RL = 10kΩ, VSS = –5V
No Oscillation
VREF
–1.25
L
VREF
+1.25
H
✻
✻
✻
✻
V
mA
pF
500
–10, +30
Indefinite
✻
✻
✻
mA
GND or VCC or VSS
REFERENCE INPUT
Ref High Input Voltage Range
Ref Low Input Voltage Range
Ref High Input Current
VREFL + 1.25
–2.5
+2.5
VREFH – 1.25
✻
✻
✻
✻
V
V
µA
µA
500
–500
✻
✻
Ref Low Input Current
DYNAMIC PERFORMANCE
Settling Time
Channel-to-Channel Crosstalk
Digital Feedthrough
Output Noise Voltage
DAC Glitch
To ±0.003%, 5V Output Step
8
0.5
2
60
40
10
✻
✻
✻
✻
✻
✻
µs
LSB
nV-s
nV/√Hz
nV-s
See Figure 5.
f = 10kHz
7FFFH to 8000H or 8000H to 7FFFH
DIGITAL INPUT
VIH
VIL
IIH
0.7 • VDD
✻
✻
V
V
µA
µA
0.3 • VDD
±10
±10
✻
✻
✻
IIL
DIGITAL OUTPUT
VOH
VOL
IOH = –0.8mA
IOL = 1.2mA
3.6
4.5
0.3
✻
✻
V
V
0.4
✻
POWER SUPPLY
VDD
VCC
VSS
ICC
IDD
ISS
+4.75
+4.75
–5.25
+5.0
+5.0
–5.0
1.5
50
–1.5
15
+5.25
+5.25
–4.75
2
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
V
V
V
mA
µA
mA
mW
–2.3
–40
✻
✻
Power
20
✻
✻
TEMPERATURE RANGE
Specified Performance
+85
°C
✻ Specifications same as DAC7644E.
The information provided herein is believed to be reliable; however, BURR-BROWN assumes no responsibility for inaccuracies or omissions. BURR-BROWN assumes
no responsibility for the use of this information, and all use of such information shall be entirely at the user’s own risk. Prices and specifications are subject to change
without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not authorize or warrant
any BURR-BROWN product for use in life support devices and/or systems.
®
2
DAC7644
SPECIFICATIONS (Single Supply)
At TA = TMIN to TMAX, VDD = VCC = +5V, VSS = 0V, VREFH = +2.5V, and VREFL = 0V, unless otherwise noted.
DAC7644E
DAC7644EB
TYP
PARAMETER
CONDITIONS
MIN
TYP
MAX
MIN
MAX
UNITS
ACCURACY
Linearity Error(1)
Linearity Match
Differential Linearity Error
Monotonicity, TMIN to TMAX
Zero Scale Error
Zero Scale Error Drift
Full-Scale Error
Full-Scale Error Drift
Zero Scale Matching
Full-Scale Matching
Power Supply Rejection Ratio (PSRR)
±3
±4
±2
±4
±3
±2
±2
±1
±3
±2
LSB
LSB
LSB
Bits
mV
ppm/°C
mV
ppm/°C
mV
mV
ppm/V
14
15
±1
5
±1
5
±1
±1
10
±2
10
±2
10
±2
✻
✻
✻
✻
✻
✻
✻
✻
Channel-to-Channel Matching
Channel-to-Channel Matching
At Full Scale
±1
±1
✻
±2
±2
✻
±2
100
ANALOG OUTPUT
Voltage Output
Output Current
Maximum Load Capacitance
Short-Circuit Current
Short-Circuit Duration
VREFL = 0V, VSS = 0V, RL = 10kΩ
No Oscillation
0
VREF
+1.25
H
✻
✻
✻
✻
V
mA
pF
–1.25
500
±30
Indefinite
✻
✻
✻
mA
GND or VCC
REFERENCE INPUT
Ref High Input Voltage Range
Ref Low Input Voltage Range
Ref High Input Current
VREFL + 1.25
0
+2.5
VREFH – 1.25
✻
✻
✻
✻
V
V
µA
µA
250
–250
✻
✻
Ref Low Input Current
DYNAMIC PERFORMANCE
Settling Time
Channel-to-Channel Crosstalk
Digital Feedthrough
Output Noise Voltage, f = 10kHz
DAC Glitch
To ±0.003%, 2.5V Output Step
8
0.5
2
60
40
10
✻
✻
✻
✻
✻
✻
µs
LSB
nV-s
nV/√Hz
nV-s
See Figure 6.
7FFFH to 8000H or 8000H to 7FFFH
DIGITAL INPUT
VIH
VIL
IIH
0.7 • VDD
✻
✻
V
V
µA
µA
0.3 • VDD
±10
±10
✻
✻
✻
IIL
DIGITAL OUTPUT
VOH
VOL
IOH = –0.8mA
IOL = 1.2mA
3.6
4.5
0.3
✻
✻
V
V
0.4
✻
POWER SUPPLY
VDD
VCC
VSS
ICC
IDD
Power
+4.75
+4.75
0
+5.0
+5.0
0
1.5
50
+5.25
+5.25
0
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
V
V
V
mA
µA
mW
2
7.5
10
✻
✻
TEMPERATURE RANGE
Specified Performance
–40
+85
✻
°C
NOTE: (1) If VSS = 0V specification applies at Code 0040H and above due to possible negative zero-scale error.
✻ Specifications same as DAC7644E.
®
3
DAC7644
ABSOLUTE MAXIMUM RATINGS(1)
ELECTROSTATIC
DISCHARGE SENSITIVITY
This integrated circuit can be damaged by ESD. Burr-Brown
recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling
and installation procedures can cause damage.
VCC and VDD to VSS .............................................................. –0.3V to 11V
VCC and VDD to GND ........................................................... –0.3V to 5.5V
VREFL to VSS ............................................................. –0.3V to (VCC – VSS
VCC to VREFH ............................................................ –0.3V to (VCC – VSS
VREFH to VREFL ......................................................... –0.3V to (VCC – VSS
Digital Input Voltage to GND ................................... –0.3V to VDD + 0.3V
Digital Output Voltage to GND ................................. –0.3V to VDD + 0.3V
Maximum Junction Temperature ................................................... +150°C
Operating Temperature Range ........................................–40°C to +85°C
Storage Temperature Range ......................................... –65°C to +125°C
Lead Temperature (soldering, 10s)............................................... +300°C
)
)
)
ESD damage can range from subtle performance degradation
to complete device failure. Precision integrated circuits may
be more susceptible to damage because very small parametric
changes could cause the device not to meet its published
specifications.
NOTE: (1) Stresses above those listed under “Absolute Maximum Ratings”
may cause permanent damage to the device. Exposure to absolute maximum
conditions for extended periods may affect device reliability.
PACKAGE/ORDERING INFORMATION
LINEARITY
ERROR
(LSB)
DIFFERENTIAL
NONLINEARITY
(LSB)
PACKAGE
DRAWING
NUMBER(1)
SPECIFICATION
TEMPERATURE
RANGE
ORDERING
NUMBER(2)
TRANSPORT
MEDIA
PRODUCT
PACKAGE
DAC7644E
±4
"
±3
"
±3
"
±2
"
48-Lead SSOP
333
"
333
"
–40°C to +85°C
DAC7644E
DAC7644E/1K
DAC7644EB
Rails
Tape and Reel
Rails
"
"
"
DAC7644EB
48-Lead SSOP
–40°C to +85°C
"
"
"
DAC7644EB/1K
Tape and Reel
NOTES: (1) For detailed drawing and dimension table, please see end of data sheet, or Appendix C of Burr-Brown IC Data Book. (2) Models with a slash (/)
are available only in Tape and Reel in the quantities indicated (e.g., /1K indicates 1000 devices per reel). Ordering 1000 pieces of “DAC7644/1K” will get a single
1000-piece Tape and Reel. For detailed Tape and Reel mechanical information, refer to Appendix B of Burr-Brown IC Data Book.
®
4
DAC7644
PIN CONFIGURATION
Top View
SSOP
DB15
DB14
DB13
DB12
DB11
DB10
DB9
1
2
3
4
5
6
7
8
9
48 NC
47 NC
46 NC
45 NC
44 VOUTA Sense
43 VOUT
A
42 VREFL AB Sense
41 VREFL AB
DB8
DB7
40 VREFH AB
DB6 10
DB5 11
39 VREFH AB Sense
38 VOUTB Sense
DB4 12
37 VOUT
36 VOUTC Sense
35 VOUT
B
DAC7644
DB3 13
DB2 14
C
DB1 15
34 VREFH CD Sense
33 VREFH CD
DB0 16
RSTSEL 17
RST 18
32 VREFL CD
31 VREFL CD Sense
30 VOUTD Sense
LOADDACS 19
R/W 20
29 VOUT
28 VSS
D
A1 21
A0 22
27 AGND
26 VCC
25 VDD
CS 23
DGND 24
PIN DESCRIPTIONS
PIN
NAME
DESCRIPTION
PIN
NAME
DESCRIPTION
1
2
DB15
DB14
DB13
DB12
DB11
DB10
DB9
Data Bit 15, MSB
Data Bit 14
Data Bit 13
Data Bit 12
Data Bit 11
Data Bit 10
Data Bit 9
23
24
CS
DGND
VDD
Chip Select. Active LOW.
Digital Ground
3
25
26
27
28
29
30
Positive Power Supply (digital)
Positive Power Supply (analog)
Analog Ground
4
VCC
5
AGND
VSS
6
Negative Power Supply
DAC D Voltage Output
7
VOUTD
8
DB8
Data Bit 8
VOUTD Sense
DAC D’s Output Amplifier Inverting Input. Used to
close the feedback loop at the load.
9
DB7
Data Bit 7
31
32
33
34
35
36
VREFL CD Sense DAC C and D Reference Low Sense Input
10
11
12
13
14
15
16
17
DB6
Data Bit 6
V
REFL CD
DAC C and D Reference Low Input
DAC C and D Reference High Input
DB5
Data Bit 5
VREFH CD
DB4
Data Bit 4
VREFH CD Sense DAC C and D Reference High Sense Input
DB3
Data Bit 3
VOUTC
DAC C Voltage Output
DB2
Data Bit 2
V
V
OUTC Sense
DAC C’s Output Amplifier Inverting Input. Used to
close the feedback loop at the load.
DB1
Data Bit 1
DB0
Data Bit 0, LSB
37
38
VOUTB
DAC B Voltage Output
RSTSEL
Reset Select. Determines the action of RST. If
HIGH, a RST command will set the DAC registers to
mid-scale. IfLOW, aRSTcommandwillsettheDAC
registers to zero.
OUTB Sense
DAC B’s Output Amplifier Inverting Input. Used to
close the feedback loop at the load.
39
40
41
42
43
44
VREFH AB Sense DAC A and B Reference High Sense Input
18
RST
Reset, Rising Edge Triggered. Depending on the
state of RSTSEL, the DAC registers are set to either
mid-scale or zero.
V
REFH AB
DAC A and B Reference High Input
DAC A and B Reference Low Input
V
REFL AB
VREFL AB Sense DAC A and B Reference Low Sense Input
19
20
21
22
LOADDACS
DAC Output Registers Load Control. Rising edge
triggered.
VOUTA
DAC A Voltage Input
V
OUTA Sense
DAC A’s Output Amplifier Inverting Input. Used to
close the feedback loop at the load.
R/W
A1
Enabled by the CS, Controls Data Read and Write
from the Input Registers.
45
46
47
48
NC
NC
NC
NC
No Connection
No Connection
No Connection
No Connection
Enabled by the CS, in Combination With A0 Selects
the Individual DAC Input Registers.
A0
Enabled by the CS, in Combination With A1 Selects
the Individual DAC Input Registers.
®
5
DAC7644
TYPICAL PERFORMANCE CURVES: VSS = 0V
At TA = +25°C, VDD = VCC = +5V, VSS = 0V, VREFH = +2.5V, VREFL = 0V, representative unit, unless otherwise specified.
+25°C
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC A, +25°C)
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC B, +25°C)
2.0
1.5
2.0
1.5
1.0
1.0
0.5
0
0.5
0
–0.5
–1.0
–1.5
–2.0
–0.5
–1.0
–1.5
–2.0
2.0
1.5
2.0
1.5
1.0
1.0
0.5
0
0.5
0
–0.5
–1.0
–1.5
–2.0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Digital Input Code
Digital Input Code
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC C, +25°C)
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC D, +25°C)
2.0
2.0
1.5
1.0
1.5
1.0
0.5
0
0.5
0
–0.5
–1.0
–1.5
–2.0
–0.5
–1.0
–1.5
–2.0
2.0
1.5
2.0
1.5
1.0
1.0
0.5
0
0.5
0
–0.5
–1.0
–1.5
–2.0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Digital Input Code
Digital Input Code
+85°C
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC B, +85°C)
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC B, +85°C)
2.0
1.5
2.0
1.5
1.0
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0.5
0
–0.5
–1.0
–1.5
–2.0
2.0
1.5
2.0
1.5
1.0
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Digital Input Code
Digital Input Code
®
6
DAC7644
TYPICAL PERFORMANCE CURVES: VSS = 0V (CONT)
At TA = +25°C, VDD = VCC = +5V, VSS = 0V, VREFH = +2.5V, VREFL = 0V, representative unit, unless otherwise specified.
+85°C (cont)
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC C, +85°C)
(DAC D, +85°C)
2.0
1.5
2.0
1.5
1.0
1.0
0.5
0
0.5
0
–0.5
–1.0
–1.5
–2.0
–0.5
–1.0
–1.5
–2.0
2.0
1.5
2.0
1.5
1.0
1.0
0.5
0
0.5
0
–0.5
–1.0
–1.5
–2.0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Digital Input Code
Digital Input Code
–40°C
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC A, –40°C)
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC B, –40°C)
2.0
1.5
2.0
1.5
1.0
1.0
0.5
0
0.5
0
–0.5
–1.0
–1.5
–2.0
–0.5
–1.0
–1.5
–2.0
2.0
1.5
2.0
1.5
1.0
1.0
0.5
0
0.5
0
–0.5
–1.0
–1.5
–2.0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Digital Input Code
Digital Input Code
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC C, –40°C)
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC D, –40°C)
2.0
2.0
1.5
1.5
1.0
1.0
0.5
0
0.5
0
–0.5
–1.0
–1.5
–2.0
–0.5
–1.0
–1.5
–2.0
2.0
1.5
2.0
1.5
1.0
1.0
0.5
0
0.5
0
–0.5
–1.0
–1.5
–2.0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Digital Input Code
Digital Input Code
®
7
DAC7644
TYPICAL PERFORMANCE CURVES: VSS = 0V (CONT)
At TA = +25°C, VDD = VCC = +5V, VSS = 0V, VREFH = +2.5V, VREFL = 0V, representative unit, unless otherwise specified.
FULL-SCALE ERROR vs TEMPERATURE
Code (FFFFH)
ZERO-SCALE ERROR vs TEMPERATURE
Code (0040H)
2
1.5
1
2
1.5
1
DAC B
DAC C
DAC C
DAC D
0.5
0
0.5
0
–0.5
–1
–0.5
–1
DAC A
DAC D
DAC A
DAC B
–1.5
–2
–1.5
–2
–40
–25
0
25
55
85
–40
–25
0
25
55
85
Temperature (°C)
Temperature (°C)
VREFH CURRENT vs CODE
(all DACs sent to indicated code)
VREFL CURRENT vs CODE
(all DACs sent to indicated code)
0.30
0.25
0.20
0.15
0.10
0.05
0.00
0.00
–0.05
–0.10
–0.15
–0.20
–0.25
–0.30
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Digital Input Code
Digital Input Code
POSITIVE SUPPLY CURRENT
vs DIGITAL INPUT CODE
POSITIVE SUPPLY CURRENT vs TEMPERATURE
2
2
No Load
Data = FFFFH (all DACs)
No Load
1.5
1.5
All DACs
One DAC
1
0.5
0
1
0.5
0
–40
–25
0
25
55
85
0000H 0200H 0400H 0800H 1000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Temperature (°C)
Digital Input Code
®
8
DAC7644
TYPICAL PERFORMANCE CURVES: VSS = 0V (CONT)
At TA = +25°C, VDD = VCC = +5V, VSS = 0V, VREFH = +2.5V, VREFL = 0V, representative unit, unless otherwise specified.
OUTPUT VOLTAGE vs SETTLING TIME
OUTPUT VOLTAGE vs SETTLING TIME
(0V to +2.5V)
(+2.5V to 2mV)
+5V
LDAC
0
+5V
LDAC
0
Large-Signal Settling Time: 0.5V/div
Small-Signal Settling Time: 4LSB/div
Small-Signal Settling Time: 4LSB/div
Large-Signal Settling Time: 0.5V/div
Time (2µs/div)
Time (2µs/div)
OUTPUT VOLTAGE
OUTPUT VOLTAGE
vs MIDSCALE GLITCH PERFORMANCE
vs MIDSCALE GLITCH PERFORMANCE
+5V
LDAC
0
+5V
LDAC
0
7FFFH to 8000H
8000H to 7FFFH
Time (1µs/div)
Time (1µs/div)
BROADBAND NOISE
OUTPUT NOISE VOLTAGE vs FREQUENCY
1000
100
10
BW = 10kHz
Code = 8000H
10
100
1000
10000
100000
1000000
Time (10µs/div)
Frequency (Hz)
®
9
DAC7644
TYPICAL PERFORMANCE CURVES: VSS = 0V (CONT)
At TA = +25°C, VDD = VCC = +5V, VSS = 0V, VREFH = +2.5V, VREFL = 0V, representative unit, unless otherwise specified.
LOGIC SUPPLY CURRENT
vs LOGIC INPUT LEVEL FOR DATA BITS
VOUT vs RLOAD
5
4
3
2
1
0
12
10
8
Source
6
4
2
Sink
0
0.01
0.1
1
10
100
0
1
2
3
4
5
RLOAD (kΩ)
Logic Input Level for Data Bits (V)
®
10
DAC7644
TYPICAL PERFORMANCE CURVES: VSS = –5V
At TA = +25°C, VDD = VCC = +5V, VSS = –5V, VREFH = +2.5V, VREFL = –2.5V, representative unit, unless otherwise specified.
+25°C
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC A, +25°C)
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC B, +25°C)
2.0
1.5
1.0
0.5
1.0
0
0.5
0
–0.5
–1.0
–1.5
–2.0
–0.5
–1.0
–1.5
–2.0
–2.5
–3.0
2.0
1.5
2.0
1.5
1.0
1.0
0.5
0
0.5
0
–0.5
–1.0
–1.5
–2.0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Digital Input Code
Digital Input Code
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC D, +25°C)
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC C, +25°C)
1.0
2.0
1.5
0.5
0
1.0
–0.5
–1.0
–1.5
–2.0
–2.5
–3.0
0.5
0
–0.5
–1.0
–1.5
–2.0
1.0
0.5
2.0
1.5
0
1.0
–0.5
–1.0
–1.5
–2.0
–2.5
–3.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Digital Input Code
Digital Input Code
+85°C
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC B, +85°C)
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC A, +85°C)
1.0
0.5
0
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
–2.5
–3.0
–0.5
–1.0
–1.5
–2.0
–2.5
–3.0
1.0
0.5
2.0
1.5
0
1.0
–0.5
–1.0
–1.5
–2.0
–2.5
–3.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Digital Input Code
Digital Input Code
®
11
DAC7644
TYPICAL PERFORMANCE CURVES: VSS = –5V (CONT)
At TA = +25°C, VDD = VCC = +5V, VSS = –5V, VREFH = +2.5V, VREFL = –2.5V, representative unit, unless otherwise specified.
+85°C (cont)
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC C, +85°C)
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC D, +85°C)
1.5
1.0
1.0
0.5
0.5
0
0
–0.5
–1.0
–1.5
–2.0
–2.5
–3.0
–0.5
–1.0
–1.5
–2.0
–2.5
2.0
1.5
1.0
0.5
1.0
0
0.5
0
–0.5
–1.0
–1.5
–2.0
–0.5
–1.0
–1.5
–2.0
–2.5
–3.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Digital Input Code
Digital Input Code
–40°C
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC B, –40°C)
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC A, –40°C)
1.5
2.0
1.5
1.0
0.5
1.0
0
0.5
0
–0.5
–1.0
–1.5
–2.0
–0.5
–1.0
–1.5
–2.0
–2.5
2.0
1.5
2.0
1.5
1.0
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Digital Input Code
Digital Input Code
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC C, –40°C)
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC D, –40°C)
1.5
1.5
1.0
1.0
0.5
0.5
0
0
–0.5
–1.0
–1.5
–2.0
–2.5
–0.5
–1.0
–1.5
–2.0
–2.5
2.0
1.5
1.5
1.0
1.0
0.5
0.5
0
–0.5
–1.0
–1.5
–2.0
0
–0.5
–1.0
–1.5
–2.0
–2.5
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Digital Input Code
Digital Input Code
®
12
DAC7644
TYPICAL PERFORMANCE CURVES: VSS = –5V (CONT)
At TA = +25°C, VDD = VCC = +5V, VSS = –5V, VREFH = +2.5V, VREFL = –2.5V, representative unit, unless otherwise specified.
VREFL CURRENT vs CODE
(all DACs sent to indicated code)
VREFH CURRENT vs CODE
(all DACs sent to indicated code)
0.0
–0.1
–0.2
–0.3
–0.4
–0.5
–0.6
+0.6
+0.5
+0.4
+0.3
+0.2
+0.1
0.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Digital Input Code
Digital Input Code
POSITIVE FULL-SCALE ERROR vs TEMPERATURE
ZERO-SCALE ERROR vs TEMPERATURE
(Code FFFFH)
(Code 8000H)
2
1.5
2
1.5
1
0.5
0
1
0.5
0
DAC A
DAC B
DAC A
DAC B
DAC D
–0.5
–1
–0.5
–1
DAC C
DAC D
DAC C
–1.5
–2
–1.5
–2
–40
–25
0
25
55
85
–40
–25
0
25
55
85
Temperature (°C)
Temperature (°C)
POWER SUPPLY CURRENT
vs TEMPERATURE
NEGATIVE FULL-SCALE ERROR vs TEMPERATURE
(Code 0000H)
3
2.5
2
2
1.5
1
Data = FFFFH (all DACs)
No Load
ICC
1.5
1
DAC D
DAC A
DAC C
0.5
0
0.5
0
–0.5
–1
–0.5
–1
DAC B
ISS
–1.5
–2
–1.5
–2
–2.5
–3
–40
–25
0
25
55
85
–40
–25
0
25
55
85
Temperature (°C)
Temperature (°C)
®
13
DAC7644
TYPICAL PERFORMANCE CURVES: VSS = –5V (CONT)
At TA = +25°C, VDD = VCC = +5V, VSS = –5V, VREFH = +2.5V, VREFL = –2.5V, representative unit, unless otherwise specified.
POSITIVE SUPPLY CURRENT
vs DIGITAL INPUT CODE
VOUT vs RLOAD
5
4
2
1.5
1
No Load
All DACs
Source
3
2
One DAC
1
0
–1
–2
–3
–4
–5
Sink
0.5
0
0000H 0200H 0400H 0800H 1000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
0.01
0.1
1
10
100
Digital Input Code
RLOAD (kΩ)
OUTPUT VOLTAGE vs SETTLING TIME
(–2.5V to +2.5V)
OUTPUT VOLTAGE vs SETTLING TIME
(+2.5V to –2.5V)
+5V
+5V
LDAC
0
LDAC
0
Large-Signal Settling Time: 1V/div
Small-Signal Settling Time: 2LSB/div
Small-Signal Settling Time:
2LSB/div
Large-Signal Settling Time: 1V/div
Time (2µs/div)
Time (2µs/div)
®
14
DAC7644
by the external voltage references (VREFL and VREFH, re-
spectively). The digital input is a 16-bit parallel word and
the DAC input registers offer a readback capability. The
converters can be powered from either a single +5V supply
or a dual ±5V supply. The device offers a reset function
which immediately sets all DAC output voltages and DAC
registers to mid-scale code 8000H or to zero-scale, code
0000H. See Figures 2 and 3 for the basic operation of the
DAC7644.
THEORY OF OPERATION
The DAC7644 is a quad voltage output, 16-bit digital-to-
analog converter (DAC). The architecture is an R-2R ladder
configuration with the three MSB’s segmented followed by
an operational amplifier that serves as a buffer. Each DAC
has its own R-2R ladder network, segmented MSBs and
output op amp (see Figure 1). The minimum voltage output
(zero-scale) and maximum voltage output (full-scale) are set
RF
VOUT Sense
VOUT
R
2R
2R
2R
2R
2R
2R
2R
2R
2R
VREF
VREFH Sense
VREF
H
L
VREFL Sense
FIGURE 1. DAC7644 Architecture.
1
2
3
4
5
6
7
8
9
DB15
NC 48
DB14
DB13
DB12
DB11
DB10
DB9
NC 47
NC 46
NC 45
V
OUTA Sense 44
0V to +2.5V
+2.5000V
VOUT
REFL AB Sense 42
REFL AB 41
REFH AB 40
A
43
V
DB8
V
Data
Bus
DB7
V
10 DB6
11 DB5
12 DB4
13 DB3
14 DB2
15 DB1
16 DB0
17 RSTSEL
18 RST
19 LOADDACS
20 R/W
21 A1
V
REFH AB Sense 39
VOUTB Sense 38
0V to +2.5V
0V to +2.5V
+2.5000V
V
OUTB 37
OUTC Sense 36
OUTC 35
DAC7644
V
V
V
REFH CD Sense 34
VREFH CD 33
V
REFL CD 32
REFL CD Sense 31
OUTD Sense 30
VOUT
29
Reset DACs
Load DAC Registers
READ/WRITE
V
V
0V to +2.5V
D
VSS 28
AGND 27
VCC 26
Address
22 A0
0.1µF
1µF
Chips Select
23 CS
+
+5V
24 DGND
VDD 25
NC = No Connection
FIGURE 2. Basic Single-Supply Operation of the DAC7644.
15
®
DAC7644
1
2
3
4
5
6
7
8
9
DB15
DB14
DB13
DB12
DB11
DB10
DB9
NC 48
NC 47
NC 46
NC 45
V
OUTA Sense 44
–2.5V to +2.5V
V
OUTA 43
VREFL AB Sense 42
VREFL AB 41
–2.5V
+2.5V
DB8
Data
Bus
DB7
V
REFH AB 40
VREFH AB Sense 39
OUTB Sense 38
VOUT
37
OUTC Sense 36
VOUT
35
10 DB6
11 DB5
12 DB4
13 DB3
14 DB2
15 DB1
16 DB0
17 RSTSEL
18 RST
19 LOADDACS
20 R/W
21 A1
V
–2.5V to +2.5V
–2.5V to +2.5V
B
DAC7644
V
C
V
REFH CD Sense 34
+2.5V
–2.5V
VREFH CD 33
+5V
Reset DACs
VREFL CD 32
V
REFL CD Sense 31
Load DAC Registers
READ/WRITE
VOUTD Sense 30
–2.5V to +2.5V
V
OUTD 29
VSS 28
–5V
+5V
Address
0.1µF
1.0µF
1.0µF
+
+
22 A0
AGND 27
VCC 26
VDD 25
0.1µF
Chips Select
23 CS
24 DGND
NC = No Connection
FIGURE 3. Basic Dual-Supply Operation of the DAC7644.
The DAC7644 offers a force and sense output configuration
for the high open-loop gain output amplifier. This feature
allows the loop around the output amplifier to be closed at
the load (see Figure 4), thus ensuring an accurate output
voltage.
ANALOG OUTPUTS
When VSS = –5V (dual supply operation), the output ampli-
fier can swing to within 2.25V of the supply rails, guaran-
teed over the –40°C to +85°C temperature range. With VSS
= 0V (single-supply operation), and with RLOAD also con-
nected to ground, the output can swing to ground. Care must
also be taken when measuring the zero-scale error when VSS
= 0V. Since the output voltage cannot swing below ground,
the output voltage may not change for the first few digital
input codes (0000H, 0001H, 0002H, etc.) if the output ampli-
fier has a negative offset. At the negative limit of –2mV, the
first specified output starts at code 0040H.
NC 48
NC 47
NC 46
RW1
NC 45
V
OUTA Sense 44
OUTA 43
VREFL AB Sense 42
REFL AB 41
REFH AB 40
RW2
Due to the high accuracy of these D/A converters, system
design problems such as grounding and contact resistance
become very important. A 16-bit converter with a 2.5V full-
scale range has a 1LSB value of 38µV. With a load current
of 1mA, series wiring and connector resistance (see Figure
4) of only 40mΩ (RW2) will cause a voltage drop of 40µV.
To understand what this means in terms of a system layout,
the resistivity of a typical 1 ounce copper-clad printed circuit
board is 1/2 mΩ per square. For a 1mA load, a 10 milli-inch
wide printed circuit conductor 600 milli-inches long will
result in a voltage drop of 30µV.
VOUT
+V
V
DAC7644
V
V
+2.5V
VREFH AB Sense 39
RW1
VOUTB Sense 38
V
OUTB 37
RW2
VOUT
FIGURE 4. Analog Output Closed-Loop Configuration
(1/2 DAC7644). RW represents wiring resis-
tances.
®
16
DAC7644
REFERENCE INPUTS
The current into the VREFH input and out of VREFL depends
on the DAC output voltages and can vary from a few
microamps to approximately 0.5mA. The reference input
appears as a varying load to the reference. If the reference
can sink or source the required current, a reference buffer is
not required. The DAC7644 features a reference drive and
sense connection such that the internal errors caused by the
changing reference current and the circuit impedances can
be minimized. Figures 5 through 12 show different reference
configurations and the effect on the linearity and differential
linearity.
The reference inputs, VREFL and VREFH, can be any voltage
between VSS + 2.5V and VCC – 2.5V provided that VREFH is
at least 1.25V greater than VREFL. The minimum output of
each DAC is equal to VREFL plus a small offset voltage
(essentially, the offset of the output op amp). The maximum
output is equal to VREFH plus a similar offset voltage. Note
that VSS (the negative power supply) must either be
connected to ground or must be in the range of –4.75V to
–5.25V. The voltage on VSS sets several bias points within
the converter. If VSS is not in one of these two configura-
tions, the bias values may be in error and proper operation
of the device is not guaranteed.
NC 48
NC 47
NC 46
NC 45
+V
V
OUTA Sense 44
OUTA 43
REFL AB Sense 42
REFL AB 41
REFH AB 40
REFH AB Sense 39
OUTB Sense 38
OUTB 37
OPA2234
VOUT
V
DAC7644
V
–2.5V
V
500pF
V
–V
+V
V
500pF
V
V
VOUT
+2.5V
–V
FIGURE 5. Dual Supply Configuration-Buffered References, used for Dual Supply Performance Curves (1/2 DAC7644).
NC 48
NC 47
NC 46
+V
NC 45
VOUTA Sense 44
OPA2350
VOUT
V
OUTA 43
REFL AB Sense 42
REFL AB 41
REFH AB 40
REFH AB Sense 39
OUTB Sense 38
OUTB 37
DAC7644
V
2kΩ
100Ω
100Ω
2200pF
2200pF
V
1000pF
1000pF
0.050V
V
+V
98kΩ
V
V
+2.5V
V
VOUT
NOTE: VREFL has been chosen to be 50mV to allow for current sinking voltage
drops across the 100Ω resistor and the output stage of the buffer op amp.
FIGURE 6. Single-Supply Buffered Reference with a Reference Low of 50mV (1/2 DAC7644).
®
17
DAC7644
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC A, +25°C)
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC A, +25°C)
2.5
2.0
2.0
1.5
1.5
1.0
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0.5
0
–0.5
–1.0
–1.5
2.5
2.0
2.0
1.5
1.5
1.0
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0.5
0
–0.5
–1.0
–1.5
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Digital Input Code
Digital Input Code
FIGURE 8. Integral Linearity and Differential Linearity
Error Curves for Figure 9.
FIGURE 7. Integral Linearity and Differential Linearity
Error Curves for Figure 6.
NC 48
NC 47
NC 46
NC 45
+V
V
OUTA Sense 44
VOUT
43
REFL AB Sense 42
REFL AB 41
REFH AB 40
VREFH AB Sense 39
OUTB Sense 38
OUTB 37
+V
OPA2350
VOUT
A
DAC7644
V
100Ω
100Ω
2200pF
2200pF
+1.25V
V
1000pF
1000pF
V
+V
V
V
+2.5V
VOUT
FIGURE 9. Single-Supply Buffered Reference with VREFL = +1.25V and VREFH = +2.5V (1/2 DAC7644).
NC 48
NC 47
NC 46
NC 45
V
OUTA Sense 44
VOUT
43
REFL AB Sense 42
REFL AB 41
VREFH AB 40
REFH AB Sense 39
OUTB Sense 38
VOUT
37
VOUT
A
DAC7644
+V
V
V
+V
OPA350
100Ω
+2.5V
V
1000pF
2200pF
V
VOUT
B
FIGURE 10. Single-Supply Buffered VREFH (1/2 DAC7644).
®
18
DAC7644
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC A, +25°C)
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC A, +25°C)
2.5
2.0
3.0
2.5
2.0
1.5
1.0
0.5
0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–0.5
–1.0
2.0
1.5
2.0
1.5
1.0
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Digital Input Code
Digital Input Code
FIGURE 13. Linearity and Differential Linearity Error Curves
for Figure 12.
FIGURE 11. Linearity and Differential Linearity Error Curves
for Figure 10.
DIGITAL INTERFACE
Table I shows the basic control logic for the DAC7644. Note
that each internal register is edge triggered and not level
triggered. When the LOADDACS signal is transitioned to
HIGH, the digital word currently in the register is latched.
The first set of registers (the input registers) are triggered via
the A0, A1, R/W, and CS inputs. Only one of these registers
is transparent at any given time.
NC 48
NC 47
NC 46
NC 45
V
OUTA Sense 44
OUTA 43
REFL AB Sense 42
REFL AB 41
REFH AB 40
REFH AB Sense 39
OUTB Sense 38
OUTB 37
VOUT
V
DAC7644
The double-buffered architecture is designed mainly so each
DAC input register can be written to at any time and then all
DAC voltages updated simultaneously by the rising edge of
LOADDACS. It also allows a DAC input register to be
written to at any point and the DAC voltages to be synchro-
nously changed via a trigger signal connected to
LOADDACS.
V
+V
V
+2.5V
V
V
V
VOUT
V
FIGURE 12. Low Cost Single-Supply Configuration.
INPUT
DAC
A1
A0
R/W
CS
RST
RSTSEL LOADDACS
REGISTER
REGISTER
MODE
DAC
L
L
H
H
L
L
H
L
H
L
L
L
L
L
L
L
L
L
L
L
L
H
H
X
X
H
H
H
H
H
H
H
H
H
H
↑
X
X
X
X
X
X
X
X
X
X
L
X
X
X
X
X
X
X
X
↑
Write
Write
Write
Write
Read
Read
Read
Read
Hold
Hold
Hold
Hold
Hold
Hold
Hold
Hold
Hold
Write
Write Input
Write Input
Write Input
Write Input
Read Input
Read Input
Read Input
Read Input
Update
A
B
C
D
A
B
C
D
All
All
All
All
L
H
H
H
H
X
X
X
X
L
H
L
H
H
X
X
X
X
H
X
X
X
X
H
X
X
Hold
Hold
Hold
Reset to Zero
Reset to Midscale
Reset to Zero
Reset to Midscale
↑
H
TABLE I. DAC7644 Logic Truth Table.
®
19
DAC7644
DIGITAL TIMING
V
REFH – VREFL • N
(
)
Figure 14 and Table II provide detailed timing for the digital
interface of the DAC7644.
VOUT = VREFL +
(1)
65,536
DIGITAL INPUT CODING
where N is the digital input code. This equation does not
include the effects of offset (zero-scale) or gain (full-scale)
errors.
The DAC7644 input data is in Straight Binary format. The
output voltage is given by Equation 1.
tWCS
CS
tWS
tWH
R/W
tRCS
tAH
CS
tAS
tRDH
tRDS
A0/A1
tLH
R/W
tLS
tLWD
tLX
tAS
tAH
±0.003% of FSR
Error Band
LOADDACS
Data In
A0/A1
tDH
tDS
tDZ
tS
Data Out
Data Valid
tCSD
VOUT
Data Read Timing
Data Write Timing
±0.003% of FSR
Error Band
tSS
tSH
RESET SEL
tRSH
tRSS
RST
+FS
VOUT,RESET SEL LOW
–FS
+FS
MS
VOUT,RESET SEL HIGH
–FS
DAC7644 Reset Timing
FIGURE 14. Digital Input and Output Timing.
SYMBOL
DESCRIPTION
MIN
TYP
MAX
UNITS
tRCS
tRDS
tRDH
tDZ
tCSD
tWCS
tWS
tWH
tAS
tAH
tLS
tLH
tLX
tDS
tDH
tLWD
tSS
tSH
tRSS
tRSH
tS
CS LOW for Read
R/W HIGH to CS LOW
R/W HIGH after CS HIGH
CS HIGH to Data Bus in High Impedance
CS LOW to Data Bus Valid
CS LOW for Write
150
10
10
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
µs
10
100
150
100
40
0
10
0
10
30
100
100
0
10
100
0
R/W LOW to CS LOW
R/W LOW after CS HIGH
Address Valid to CS LOW
Address Valid after CS HIGH
CS LOW to LOADDACS HIGH
CS LOW after LOADDACS HIGH
LOADDACS HIGH
Data Valid to CS LOW
Data Valid after CS HIGH
LOADDACS LOW
RSTSEL Valid Before RESET HIGH
RSTSEL Valid After RESET HIGH
RESET LOW Before RESET HIGH
RESET LOW After RESET HIGH
Settling Time
200
10
10
10
TABLE II. Timing Specifications (TA = –40°C to +85°C).
®
20
DAC7644
DIGITALLY-PROGRAMMABLE
CURRENT SOURCE
Figure 15 shows a DAC7644 in a 4mA to 20mA current
output configuration. The output current can be determined
by Equation 3:
The DAC7644 offers a unique set of features that allows a
wide range of flexibility in designing applications circuits
such as programmable current sources. The DAC7644 offers
both a differential reference input as well as an open-loop
configuration around the output amplifier. The open-loop
configuration around the output amplifier allows transistor
to be placed within the loop to implement a digitally-
programmable, uni-directional current source. The availabil-
ity of a differential reference also allows programmability
for both the full-scale and zero-scale currents. The output
current is calculated as:
(3)
2.5V – 0.5V
N Value
65,536
0.5V
IOUT
=
•
+
125Ω
125Ω
At full-scale, the output current is 16mA plus the 4mA for
the zero current. At zero scale the output current is the offset
current of 4mA (0.5V/125Ω).
VREFH – VREF
RSENSE
L
N Value
65,536
(2)
IOUT
=
•
+ VREFL / RSENSE
(
)
IOUT
VPROGRAMMED
NC 48
NC 47
125Ω
NC 46
NC 45
+V
VOUTA Sense 44
OPA2350
VOUT
VREFL AB Sense 42
REFL AB 41
A
43
DAC7644
20kΩ
100Ω
2200pF
V
1000pF
1000pF
+0.5V
VREFH AB 40
VREFH AB Sense 39
VOUTB Sense 38
100Ω
80kΩ
+V
2200pF
V
OUTB 37
+2.5V
IOUT
VPROGRAMMED
125Ω
GND
FIGURE 15. 4-to-20mA Digitally Controlled Current Source (1/2 DAC7644).
®
21
DAC7644
PACKAGE OPTION ADDENDUM
www.ti.com
30-Jul-2007
PACKAGING INFORMATION
Orderable Device
DAC7644E
Status (1)
ACTIVE
ACTIVE
ACTIVE
ACTIVE
ACTIVE
ACTIVE
ACTIVE
ACTIVE
Package Package
Pins Package Eco Plan (2) Lead/Ball Finish MSL Peak Temp (3)
Qty
Type
Drawing
SSOP
DL
48
48
48
48
48
48
48
48
25 Green (RoHS & CU NIPDAU Level-3-260C-168 HR
no Sb/Br)
DAC7644E/1K
DAC7644E/1KG4
DAC7644EB
SSOP
SSOP
SSOP
SSOP
SSOP
SSOP
SSOP
DL
DL
DL
DL
DL
DL
DL
1000 Green (RoHS & CU NIPDAU Level-3-260C-168 HR
no Sb/Br)
1000 Green (RoHS & CU NIPDAU Level-3-260C-168 HR
no Sb/Br)
25 Green (RoHS & CU NIPDAU Level-3-260C-168 HR
no Sb/Br)
DAC7644EB/1K
DAC7644EB/1KG4
DAC7644EBG4
DAC7644EG4
1000 Green (RoHS & CU NIPDAU Level-3-260C-168 HR
no Sb/Br)
1000 Green (RoHS & CU NIPDAU Level-3-260C-168 HR
no Sb/Br)
25 Green (RoHS & CU NIPDAU Level-3-260C-168 HR
no Sb/Br)
25 Green (RoHS & CU NIPDAU Level-3-260C-168 HR
no Sb/Br)
(1) The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in
a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check
http://www.ti.com/productcontent for the latest availability information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements
for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered
at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and
package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS
compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame
retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material)
(3)
MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder
temperature.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is
provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the
accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take
reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on
incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited
information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI
to Customer on an annual basis.
Addendum-Page 1
PACKAGE MATERIALS INFORMATION
www.ti.com
11-Mar-2008
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device
Package Package Pins
Type Drawing
SPQ
Reel
Reel
A0 (mm)
B0 (mm)
K0 (mm)
P1
W
Pin1
Diameter Width
(mm) W1 (mm)
(mm) (mm) Quadrant
DAC7644E/1K
SSOP
SSOP
DL
DL
48
48
1000
1000
330.0
330.0
32.4
32.4
11.35
11.35
16.2
16.2
3.1
3.1
16.0
16.0
32.0
32.0
Q1
Q1
DAC7644EB/1K
Pack Materials-Page 1
PACKAGE MATERIALS INFORMATION
www.ti.com
11-Mar-2008
*All dimensions are nominal
Device
Package Type Package Drawing Pins
SPQ
Length (mm) Width (mm) Height (mm)
DAC7644E/1K
SSOP
SSOP
DL
DL
48
48
1000
1000
346.0
346.0
346.0
346.0
49.0
49.0
DAC7644EB/1K
Pack Materials-Page 2
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