BB DAC7734E

DAC7734
®
DAC
773
4
For most current data sheet and other product
information, visit www.burr-brown.com
16-Bit, Quad Voltage Output, Serial Input
DIGITAL-TO-ANALOG CONVERTER
FEATURES
DESCRIPTION
● LOW POWER: 200mW
● UNIPOLAR OR BIPOLAR OPERATION
● SINGLE SUPPLY OUTPUT RANGE: +10V
● DUAL SUPPLY OUTPUT RANGE: ±10V
● SETTLING TIME: 10µs to 0.003%
● 16-BIT MONOTONICITY: –40°C to +85°C
● PROGRAMMABLE RESET TO MID-SCALE
OR ZERO-SCALE
● DOUBLE-BUFFERED DATA INPUTS
● ±1 LSB DNL: –40°C to +85°C
The DAC7734 is a 16-bit, quad voltage output, digitalto-analog converter with guaranteed 16-bit monotonic
performance over the specified temperature range. It
accepts 24-bit serial input data, has double-buffered
DAC input logic (allowing simultaneous update of all
DACs), and provides a serial data output for daisy
chaining multiple DACs. Programmable asynchronous
reset clears all registers to a mid-scale code of 8000H or
to a zero-scale of 0000H. The DAC7734 can operate
from a single +15V supply or from +15V and –15V, and
+5V supplies.
Low power and small size per DAC make the DAC7734
ideal for automatic test equipment, DAC-per-pin programmers, data acquisition systems, and closed-loop
servo-control. The DAC7734 is available in a 48-lead
SSOP package and offers guaranteed specifications
over the –40°C to +85°C temperature range.
APPLICATIONS
● PROCESS CONTROL
● ATE PIN ELECTRONICS
● CLOSED-LOOP SERVO-CONTROL
● MOTOR CONTROL
● DATA ACQUISITION SYSTEMS
● DAC-PER-PIN PROGRAMMERS
VDD
VSS
VREFL
AB Sense
VCC
VREFL AB VREFH AB
VREFH
AB Sense
DAC7734
SDI
Shift
Register
Input
Register A
DAC
Register A
DAC A
SDO
VOUTA
VOUTA Sense
Input
Register B
DAC
Register B
Input
Register C
DAC
Register C
Input
Register D
DAC
Register D
DAC B
VOUTB
VOUTB Sense
CS
DAC C
VOUTC
CLOCK
RST
RESTSEL
LDAC
Control
Logic
VOUTC Sense
DAC D
VOUTD
LOAD
VOUTD Sense
AGND
VREFL
CD Sense
DGND
VREFL CD VREFH CD
VREFH
CD Sense
International Airport Industrial Park • Mailing Address: PO Box 11400, Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 • Tel: (520) 746-1111
Twx: 910-952-1111 • Internet: http://www.burr-brown.com/ • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132
®
© 1999 Burr-Brown Corporation
PDS-1570A
1
Printed in U.S.A. December, 1999
DAC7734
SPECIFICATIONS (Dual Supply)
At TA = TMIN to TMAX, VCC = +15V, VDD = +5V, VSS = –15V, VREFH = +10V, and VREFL = –10V, unless otherwise noted.
DAC7734E
PARAMETER
CONDITIONS
ACCURACY
Linearity Error (INL)
TMIN to TMAX
Linearity Match
Differential Linearity Error (DNL)
TMIN to TMAX
Monotonicity, TMIN to TMAX
Bipolar Zero Error
Bipolar Zero Error, TMIN to TMAX
Full-Scale Error
Full-Scale Error, TMIN to TMAX
Bipolar Zero Matching
Full-Scale Matching
Channel-to-Channel Crosstalk
Digital Feedthrough
Output Noise Voltage
MAX
MIN
TYP
±3
±4
DAC7734EC
MAX
MIN
TYP
✻
✻
MAX
UNITS
±2
±3
±0.025
±0.05
±0.025
±0.05
±0.024
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
LSB
LSB
LSB
LSB
LSB
Bits
% of FSR
% of FSR
% of FSR
% of FSR
% of FSR
Channel-to-Channel
Matching
±0.024
✻
✻
% of FSR
At Full Scale
25
✻
✻
ppm/V
✻
V
mA
pF
mA
✻
✻
V
V
mA
mA
✻
µs
±4
T = 25°C
T = 25°C
Channel-to-Channel
Matching
VREFL
±5
VREFH
VREFL + 1.25
–10
–0.3
–3.2
To ±0.003%, 20V
Output Step
See Figure 5
9
0.7 • VDD
0
DIGITAL OUTPUT
VOH
VOL
IOH = –0.8mA
IOL = 1.6mA
POWER SUPPLY
VDD
VCC
VSS
IDD
ICC
ISS
Power
3.6
+4.75
+14.25
–14.25
TEMPERATURE RANGE
Specified Performance
✻
✻
–40
+5.0
+15.0
–15.0
50
6
–5
170
✻
✻
✻
✻
✻
✻
11
✻
✻
✻
✻
✻
✻
✻
✻
✻
VDD
0.3 • VDD
±10
±10
4.5
0.3
✻
✻
✻
✻
0.5
2
60
f = 10kHz
✻
✻
✻
✻
+10
VREFH – 1.25
2.6
–0.3
LSB
nV-s
nV/√Hz
✻
V
V
µA
µA
✻
✻
✻
✻
✻
✻
✻
200
+85
✻
✻
✻
✻
0.4
+5.25
+15.75
–15.75
±1
±1
16
✻
✻
500
±20
Indefinite
To VSS, VCC or GND
DIGITAL INPUT
VIH
VIL
IIH
IIL
±2
±2
15
±0.01
±2
✻
±3
±3
14
T = 25°C
REFERENCE INPUT
Ref High Input Voltage Range
Ref Low Input Voltage Range
Ref High Input Current
Ref Low Input Current
DYNAMIC PERFORMANCE
Settling Time
TYP
T = 25°C
Power Supply Rejection Ratio (PSRR)
ANALOG OUTPUT
Voltage Output
Output Current
Maximum Load Capacitance
Short-Circuit Current
Short-Circuit Duration
MIN
DAC7734EB
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
V
V
✻
✻
✻
V
V
V
µA
mA
mA
mW
✻
°C
✻ Specifications same as grade to the left.
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.
®
DAC7734
2
SPECIFICATIONS (Single Supply)
At TA = TMIN to TMAX, VCC = +15V, VDD = +5V, VSS = GND, VREFH = +10V, and VREFL = +50mV, unless otherwise noted.
DAC7734E
PARAMETER
ACCURACY
Linearity Error(1) (INL)
TMIN to TMAX
Linearity Match
Differential Linearity Error (DNL)
TMIN to TMAX
Monotonicity, TMIN to TMAX
Unipolar Zero
Unipolar Zero Error, TMIN to TMAX
Full-Scale Error
Full-Scale Error, TMIN to TMAX
Unipolar Zero Matching
Full-Scale Matching
Power Supply Rejection Ratio (PSRR)
ANALOG OUTPUT
Voltage Output
Output Current
Maximum Load Capacitance
Short-Circuit Current
Short-Circuit Duration
CONDITIONS
Channel-to-Channel Crosstalk
Digital Feedthrough
Output Noise Voltage
MAX
MIN
TYP
±3
±4
DAC7734EC
MAX
MIN
TYP
✻
✻
MAX
UNITS
±2
±3
±0.025
±0.05
±0.025
±0.05
±0.024
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
LSB
LSB
LSB
LSB
LSB
Bits
% of FSR
% of FSR
% of FSR
% of FSR
% of FSR
Channel-to-Channel
Matching
±0.024
✻
✻
% of FSR
At Full Scale
25
✻
✻
ppm/V
✻
V
±4
14
T = 25°C
Channel-to-Channel
Matching
VREFL = 0V, VSS = 0V
R = 10kΩ
0
VREFH
±5
To ±0.003%, 10V
Output Step
See Figure 6
+10
VREFH – 1.25
1.0
–0.3
POWER SUPPLY
VDD
VCC
VSS
IDD
ICC
Power
TEMPERATURE RANGE
Specified Performance
3.6
+4.75
+14.25
–40
✻
✻
✻
✻
✻
✻
✻
✻
µs
LSB
nV-s
nV/√Hz
✻
V
V
µA
µA
✻
✻
✻
✻
✻
✻
70
+85
V
V
mA
mA
✻
✻
✻
✻
0.4
+5.25
+15.75
✻
✻
✻
✻
✻
✻
✻
4.5
0.3
mA
pF
mA
✻
✻
✻
✻
✻
10
VDD
0.3 • VDD
±10
±10
+5.0
+15.0
0
50
3.5
50
✻
✻
✻
0.5
2
60
0.7 • VDD
0
✻
✻
✻
✻
8
f = 10kHz
✻
✻
VREFL + 1.25
0
–0.3
–1.5
±1
±1
16
✻
500
±20
Indefinite
To VCC or GND
IOH = –0.8mA
IOL = 1.6mA
±2
±2
15
±0.01
T = 25°C
±2
✻
±3
±3
T = 25°C
DIGITAL INPUT
VIH
VIL
IIH
IIL
DIGITAL OUTPUT
VOH
VOL
TYP
T = 25°C
REFERENCE INPUT
Ref High Input Voltage Range
Ref Low Input Voltage Range
Ref High Input Current
Ref Low Input Current
DYNAMIC PERFORMANCE
Settling Time
MIN
DAC7734EB
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
✻
V
V
✻
✻
V
V
V
µA
mA
mW
✻
°C
✻ Specifications same as grade to the left.
NOTE: (1) If VSS = 0V, the specification applies at code 0021H and above, due to possible negative zero scale error.
®
3
DAC7734
ELECTROSTATIC
DISCHARGE SENSITIVITY
ABSOLUTE MAXIMUM RATINGS(1)
VCC to VSS ........................................................................... –0.3V to +32V
VCC to AGND ...................................................................... –0.3V to +16V
VSS to AGND ...................................................................... +0.3V to –16V
AGND to DGND ................................................................. –0.3V to +0.3V
VREFH to AGND ..................................................................... –9V to +11V
VREFL to AGND ...................................................................... –11V to +9V
VDD to GND ........................................................................... –0.3V to +6V
VREFH to VREFL ........................................................................ –1V to 22V
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 +150°C
Lead Temperature (soldering, 10s) ............................................... +300°C
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.
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
PRODUCT
LINEARITY
ERROR
(LSB)
DIFFERENTIAL
NONLINEARITY
(LSB)
DAC7734E
PACKAGE
PACKAGE
DRAWING
NUMBER
SPECIFICATION
TEMPERATURE
RANGE
±4
±3
SSOP-48
333
–40°C to +85°C
"
"
"
"
"
"
DAC7734EB
±4
±2
SSOP-48
333
–40°C to +85°C
"
"
"
"
"
"
DAC7734EC
±3
±1
SSOP-48
333
–40°C to +85°C
"
"
"
"
"
"
ORDERING
NUMBER(1)
TRANSPORT
MEDIA
DAC7734E
DAC7734E/1K
Rails
Tape and Reel
DAC7734EB
DAC7734EB/1K
Rails
Tape and Reel
DAC7734EC
DAC7734EC/1K
Rails
Tape and Reel
NOTE: (1) 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 “DAC7734E/1K” will get a single 1000-piece Tape and Reel.
ESD PROTECTION CIRCUITS
VCC
VCC
VOUT Sense
RefH
RefH Sense
VOUT
AGND
RefL Sense
RefL
VSS
VSS
1 of 2
1 of 4
VDD
VDD
Typ of Each
Logic Input Pin
DGND
DGND
SDO
®
DAC7734
4
PIN CONFIGURATION
PIN DESCRIPTIONS
Top View
NC
SSOP
1
48
VOUTA Sense
PIN
NAME
DESCRIPTION
1
NC
No Connection
2
NC
No Connection
3
SDI
DGND
Serial Data Input
NC
2
47
VOUTA
4
SDI
3
46
AGND
5
CLK
6
DGND
Digital Ground
7
LDAC
DAC Register Load Control, Rising Edge
Triggered
Digital Ground
Digital Ground
Data Clock Input
DGND
4
45
VSS
CLK
5
44
VREFL AB Sense
8
DGND
DGND
6
43
VREFL AB
9
LOAD
DAC Input Register Load Control, Active Low
LDAC
7
42
VREFH AB
10
DGND
Digital Ground
11
CS
DGND
8
41
VREFH AB Sense
12
DGND
LOAD
9
40
VOUTB Sense
13
SDO
14
DGND
15
RSTSEL
16
DGND
17
RST
DGND
10
39
VOUTB
CS
11
38
VOUTC Sense
DGND
12
37
VOUTC
DAC7734
Chip Select, Active Low
Digital Ground
Serial Data Output
Digital Ground
Reset Select. Determines the action of RST. If
HIGH, a RST common will set the DAC registers
to mid-scale (8000H). If LOW, a RST command
will set the DAC registers to zero (0000H).
Digital Ground
SDO
13
36
VREFH CD Sense
DGND
14
35
VREFH CD
RSTSEL
15
34
VREFL CD
18
DGND
Digital Ground
DGND
16
33
VREFL CD Sense
19
NC
No Connection
20
NC
No Connection
Reset, Rising Edge Triggered. Depending on the
state of RSTSEL, the DAC registers are set to
either mid-scale or zero.
RST
17
32
VOUTD Sense
21
DGND
Digital Ground
DGND
18
31
VOUTD
22
DGND
Digital Ground
23
VDD
Digital +5V Power Supply
24
VDD
Digital +5V Power Supply
25
VCC
Analog +15V Power Supply
26
VCC
Analog +15V Power Supply
27
AGND
NC
19
30
VSS
NC
20
29
VSS
DGND
21
28
AGND
Analog Ground
DGND
22
27
AGND
28
AGND
VDD
23
26
VCC
29
VSS
Analog –15V Power Supply or 0V Single Supply
30
Analog –15V Power Supply or 0V Single Supply
24
25
VSS
VDD
VCC
31
VOUTD
32
VOUTD Sense
33
VREFL CD Sense
34
VREFL CD
35
VREFH CD
36
VREFH CD Sense
37
VOUTC
38
VOUTC Sense
Analog Ground
DAC D Output Voltage
DAC D’s Output Amplifier Inverting Input. Used
to close feedback loop at load.
DAC C and D Reference Low Sense Input
DAC C and D Reference Low Input
DAC C and D Reference High Input
DAC C and D Reference High Sense Input
DAC C Output Voltage
DAC C’s Output Amplifier Inverting Input. Used
to close the feedback loop at the load.
39
VOUTB
40
VOUTB Sense
41
VREFH AB Sense
42
VREFH AB
DAC A and B Reference High Input
43
VOUTL AB
DAC A and B Reference Low Input
44
VREFL AB Sense
45
VSS
46
AGND
Analog Ground
47
VOUTA
DAC A Output Voltage
48
VOUTA Sense
DAC B Output Voltage
DAC B’s Output Amplifier Inverting Input. Used
to close the feedback loop at the load.
DAC A and B Reference High Sense Input
DAC A and B Reference Low Sense Input
Analog –15V Power Supply or 0V Single Supply
DAC A’s Output Amplifier Inverting Input. Used
to close the feedback loop at the load.
®
5
DAC7734
TYPICAL PERFORMANCE CURVES: VSS = 0V
At TA = +25°C, VDD = +5V, VCC = +15V, VSS = 0, VREFH = +10V, and VREFL = 0V, representative unit, unless otherwise specified.
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC A, +25°C)
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC B, +25°C)
LE (LSB)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
DLE (LSB)
DLE (LSB)
LE (LSB)
+25°C
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
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)
LE (LSB)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
DLE (LSB)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Digital Input Code
Digital Input Code
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC A, +85°C)
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC B, +85°C)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
LE (LSB)
LE (LSB)
+85°C
DLE (LSB)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
DLE (LSB)
DLE (LSB)
LE (LSB)
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC C, +25°C)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Digital Input Code
Digital Input Code
®
DAC7734
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
6
TYPICAL PERFORMANCE CURVES: VSS = 0V
(Cont.)
At TA = +25°C, VDD = +5V, VCC = +15V, VSS = 0, VREFH = +10V, and VREFL = 0V, representative unit, unless otherwise specified.
+85°C
(cont.)
DLE (LSB)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Digital Input Code
Digital Input Code
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC A, –40°C)
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC B, –40°C)
LE (LSB)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
DLE (LSB)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
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
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
LE (LSB)
LE (LSB)
DLE (LSB)
LE (LSB)
LE (LSB)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
–40°C
DLE (LSB)
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC D, +85°C)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
DLE (LSB)
DLE (LSB)
LE (LSB)
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC C, +85°C)
Digital Input Code
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Digital Input Code
®
7
DAC7734
TYPICAL PERFORMANCE CURVES: VSS = 0V
(Cont.)
At TA = +25°C, VDD = +5V, VCC = +15V, VSS = 0, VREFH = +10V, and VREFL = 0V, representative unit, unless otherwise specified.
POSITIVE FULL-SCALE ERROR
vs TEMPERATURE
ZERO-SCALE ERROR vs TEMPERATURE
2
Code (FFFFH)
Code (0000
(0040H)
1.5
Positive Full-Scale Error (mV)
Negative Full-Scale Error (mV)
2
1
DAC A
0.5
0
DAC C
–0.5
DAC B
DAC D
–1
–1.5
–2
DAC B
1
DAC D
0.5
0
–0.5
DAC C
DAC A
–1
–1.5
–2
–40 –30 –20 –10
0
10
20
30 40
50
60 70
80
90
–40 –30 –20 –10
0
10
20
30 40
50
60 70
REFERENCE CURRENT vs CODE
All DACs Sent to Indicated Code
(DAC A and B)
VREFH
REFERENCE CURRENT vs CODE
All DACs Sent to Indicated Code
(DAC C and D)
VREFH
VREFL
0
–0.2
–0.4
–0.6
–0.8
–1.0
–1.2
–1.4
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
VREF (Current (mA)
VREF (Current (mA)
VREF (Current (mA)
Temperature (°C)
VREF (Current (mA)
Temperature (°C)
1.0
0.8
0.6
0.4
0.2
0
–0.2
–0.4
80
90
1.0
0.8
0.6
0.4
0.2
0
–0.2
–0.4
VREFL
0
–0.2
–0.4
–0.6
–0.8
–1.0
–1.2
–1.4
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Digital Input Code
Digital Input Code
POWER SUPPLY CURRENT vs TEMPERATURE
POSITIVE SUPPLY CURRENT
vs DIGITAL INPUT CODE
4.0
4.0
Data = FFFFH (all DACs)
3.5
No Load
ICC
No Load
3.5
3.0
3.0
2.5
2.5
ICC (mA)
Quiescent Current (mA)
1.5
2.0
1.5
1.0
ICC
2.0
1.5
1.0
0.5
0.5
IDD
0
IDD
0
–0.5
–0.5
–40 –30 –20 –10
0
10
20
30 40
50
60 70
80
90
0
Temperature (°C)
4000H
6000H
8000H
A000H
Digital Input Code
®
DAC7734
2000H
8
C000H
E000H
FFFFH
TYPICAL PERFORMANCE CURVES: VSS = 0V
(Cont.)
At TA = +25°C, VDD = +5V, VCC = +15V, VSS = 0, VREFH = +10V, and VREFL = 0V, representative unit, unless otherwise specified.
OUTPUT VOLTAGE vs SETTLING TIME
(0V to +10V)
OUTPUT VOLTAGE vs SETTLING TIME
(+10V to 0V)
Small-Signal Settling Time:
3LSB/div
Output Voltage
Output Voltage
Large-Signal Settling Time: 5V/div
Small-Signal Settling Time:
3LSB/div
Large-Signal Settling Time: 5V/div
+5V
LDAC
0
+5V
LDAC
0
Time (2µs/div)
Time (2µs/div)
OUTPUT VOLTAGE
MIDSCALE GLITCH PERFORMANCE
Output Voltage (200mV/div)
Output Voltage (200mV/div)
OUTPUT VOLTAGE
MIDSCALE GLITCH PERFORMANCE
7FFFH to 8000H
8000H to 7FFFH
+5V
LDAC
0
+5V
LDAC
0
Time (1µs/div)
Time (1µs/div)
BROADBAND NOISE
OUTPUT NOISE VOLTAGE vs FREQUENCY
120
Noise (nV/√Hz)
Noise Voltage (20µV/div)
100
BW = 10kHz
Code = 8000H
80
60
40
20
0
100
Time (100µs/div)
1k
10k
100k
1M
Frequency (Hz)
®
9
DAC7734
TYPICAL PERFORMANCE CURVES: VSS = 0V
(Cont.)
At TA = +25°C, VDD = +5V, VCC = +15V, VSS = 0, VREFH = +10V, and VREFL = 0V, representative unit, unless otherwise specified.
OUTPUT VOLTAGE vs RLOAD
POWER SUPPLY REJECTION RATIO vs FREQUENCY
0
16
–10
14
–20
12
+15V
VOUT (V)
PSRR (dB)
–30
–40
–50
–60
+5V
8
6
–70
4
–80
2
–90
0
0.01
Sink
1k
100
10k
100k
0.1
1
RLOAD (kΩ)
SINGLE-SUPPLY CURRENT LIMIT vs INPUT CODE
CLOCK FEEDTHROUGH
4000H
6000H
8000H
A000H
C000H
E000H
Time (50ns/div)
FFFFH
Input Code
®
DAC7734
100
+5V
CLK
0V
Short to VCC
2000H
10
Output Voltage (5mV/div)
Short to Ground
10
5
0
–5
–10
–15
–20
–25
–30
0000H
1M
Frequency (Hz)
30
25
20
15
IOUT (mA)
Source
10
10
TYPICAL PERFORMANCE CURVES: VSS = –15V
At TA = +25°C, VDD = +5V, VCC = +15V, VSS = –15V, VREFH = +10V, and VREFL = –10V, representative unit, unless otherwise specified.
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC A, +25°C)
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC B, +25°C)
LE (LSB)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
DLE (LSB)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
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)
LE (LSB)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
DLE (LSB)
DLE (LSB)
LE (LSB)
DLE (LSB)
LE (LSB)
+25°C
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Digital Input Code
Digital Input Code
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC A, +85°C)
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC B, +85°C)
LE (LSB)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
DLE (LSB)
DLE (LSB)
LE (LSB)
+85°C
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Digital Input Code
Digital Input Code
®
11
DAC7734
TYPICAL PERFORMANCE CURVES: VSS = –15V
(Cont.)
At TA = +25°C, VDD = +5V, VCC = +15V, VSS = –15V, VREFH = +10V, and VREFL = –10V, representative unit, unless otherwise specified.
(cont.)
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC C, +85°C)
LE (LSB)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Digital Input Code
Digital Input Code
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC A, –40°C)
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC B, –40°C)
LE (LSB)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
DLE (LSB)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
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
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
LE (LSB)
LE (LSB)
DLE (LSB)
LE (LSB)
DLE (LSB)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
–40°C
DLE (LSB)
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC D, +85°C)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
DLE (LSB)
DLE (LSB)
LE (LSB)
+85°C
Digital Input Code
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Digital Input Code
®
DAC7734
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
12
TYPICAL PERFORMANCE CURVES: VSS = –15V
(Cont.)
At TA = +25°C, VDD = +5V, VCC = +15V, VSS = –15V, VREFH = +10V, and VREFL = –10V, representative unit, unless otherwise specified.
REFERENCE CURRENT vs CODE
All DACs Sent to Indicated Code
(DAC C and D)
VREFH
VREF (Current (mA)
2.5
2.0
1.5
1.0
0.5
0
–0.5
VREF (Current (mA)
VREFL
0.0
–0.5
–1.0
–1.5
–2.0
–2.5
–3.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
2.5
2.0
1.5
1.0
0.5
0
–0.5
VREFL
0.0
–0.5
–1.0
–1.5
–2.0
–2.5
–3.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Digital Input Code
Digital Input Code
BIPOLAR ZERO SCALE ERROR vs TEMPERATURE
(Code 8000H)
POSITIVE FULL-SCALE ERROR vs TEMPERATURE
(Code FFFFH)
2
2
1.5
1.5
1
Positive Full-Scale Error (mV)
Bipolar Zero Scale Error (mV)
VREF (Current (mA)
VREF (Current (mA)
REFERENCE CURRENT vs CODE
All DACs Sent to Indicated Code
(DAC A and B)
VREFH
DAC A
0.5
0
–0.5
DAC D
DAC B
DAC C
–1
–1.5
–2
–40 –30 –20 –10 0
1.0
DAC A
0.5
0
–0.5
DAC D
DAC B
–1.5
–2.0
–40 –30 –20 –10
10 20 30 40 50 60 70 80 90
0
NEGATIVE FULL-SCALE ERROR vs TEMPERATURE
(Code 0000H)
Quiescent Current (mA)
Negative Full-Scale Error (mV)
1.5
1.0
DAC A
0.5
0
DAC B
DAC C
–1.0
–1.5
–2.0
–40 –30 –20 –10
0
10
20 30
40
20 30
40
50 60
70
80
90
80
90
POWER SUPPLY CURRENT vs TEMPERTURE
2
DAC D
10
Temperature (°C)
Temperature (°C)
–0.5
DAC C
–1.0
50 60
70
80
90
7
6
5
4
3
2
1
0
–1
–2
–3
–4
–5
–6
–7
ICC
IDD
Data = FFFFH (all DACs)
No Load
–40 –30 –20 –10
Temperature (°C)
ISS
0
10
20 30
40
50 60
70
Temperature (°C)
®
13
DAC7734
TYPICAL PERFORMANCE CURVES: VSS = –15V
(Cont.)
At TA = +25°C, VDD = +5V, VCC = +15V, VSS = –15V, VREFH = +10V, and VREFL = –10V, representative unit, unless otherwise specified.
SUPPLY CURRENT vs CODE
OUTPUT VOLTAGE vs RLOAD
7
6
5
4
3
2
1
0
–1
–2
–3
–4
–5
–6
–7
15
10
Source
(mA)
VOUT (V)
5
0
–5
Sink
–10
–15
0.01
0.1
1
10
0000H
100
ICC
IDD
ISS
2000H
4000H
6000H
8000H
A000H
C000H
E000H
RLOAD (kΩ)
Digital Input Code
OUTPUT VOLTAGE vs SETTLING TIME
(–10V to +10V)
OUTPUT VOLTAGE vs SETTLING TIME
(+10V to –10V)
FFFFH
Output Voltage
Output Voltage
Large-Signal Settling Time: 5V/div
Small-Signal Settling Time: 3LSB/div
Small-Signal Settling Time: 3LSB/div
Large-Signal Settling Time: 5V/div
+5V
LDAC
0
+5V
LDAC
0
Time (2µs/div)
Time (2µs/div)
DUAL-SUPPLY CURRENT LIMIT vs INPUT CODE
(Short-to-Ground)
POWER SUPPLY REJECTION RATIO vs FREQUENCY
20
0
15
–10
–20
10
PSRR (dB)
IOUT (mA)
–30
5
0
–5
–40
–50
+15V
–70
–10
–80
–15
–90
–20
–100
0000H
–15V
–60
2000H
4000H
6000H
8000H
A000H
C000H
E000H
100
FFFFH
Digital Input Code
1k
10k
Frequency (Hz)
®
DAC7734
+5V
14
100k
1M
TYPICAL PERFORMANCE CURVES: VSS = –15V
(Cont.)
At TA = +25°C, VDD = +5V, VCC = +15V, VSS = –15V, VREFH = +10V, and VREFL = –10V, representative unit, unless otherwise specified.
OUTPUT VOLTAGE
MID-SCALE GLITCH PERFORMANCE
7FFFH to 8000H
+5V
LDAC
0
Output Voltage (200mV/div)
Output Voltage (200mV/div)
OUTPUT VOLTAGE
MID-SCALE GLITCH PERFORMANCE
8000H to 7FFFH
+5V
LDAC
0
Time (1µs/div)
Time (1µs/div)
®
15
DAC7734
THEORY OF OPERATION
The digital input is a 24-bit serial word that contains a 2-bit
address code for selecting one of four DACs, a quick load
bit, five unused bits and the 16-bit DAC code (MSB first).
The converters can be powered from either a single +15V
supply or a dual ±15V supply and a +5V logic 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 DAC7734.
The DAC7734 is a quad voltage output, 16-bit Digital-toAnalog 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, as shown in Figure 1. The
minimum voltage output (zero-scale) and maximum voltage
output (full-scale) are set by the external voltage references
VREFL and VREFH.
RF
VOUT Sense
VOUT
R
2R
2R
2R
2R
2R
2R
2R
2R
2R
VREFH
VREFH Sense
VREFL
VREFL Sense
FIGURE 1. DAC7734 Architecture.
Serial Data In
Clock
Load DAC Registers
Load
Chips Select
Serial Data Out
Reset DAC Registers
+5V
+
1µF
1
NC
VOUTA Sense
48
2
NC
VOUTA
47
3
SDI
AGND
46
4
DGND
5
CLK
6
VSS
45
VREFL AB Sense
44
DGND
VREFL AB
43
7
LDAC
VREFH AB
42
8
DGND
VREFH AB Sense
41
9
LOAD
VOUTB Sense
40
10
DGND
VOUTB
39
11
CS
VOUTC Sense
38
12
DGND
VOUTC
37
13
SDO
VREFH CD Sense
36
14
DGND
VREFH CD
35
15
RSTSEL
16
DGND
17
RST
18
DGND
19
DAC7734
VREFL CD
34
VREFL CD Sense
33
VOUTD Sense
32
VOUTD
31
NC
VSS
30
20
NC
VSS
29
21
DGND
AGND
28
22
DGND
AGND
27
23
VDD
VCC
26
24
VDD
VCC
25
0.1µF
0V to +10V
+10.000V
0V to +10V
0V to +10V
+10.000V
0V to +10V
0.1µF
+
1µF
+15V
NC = No Connection
FIGURE 2. Basic Single-Supply Operation of the DAC7734.
®
DAC7734
16
Serial Data In
Clock
Load DAC Registers
Load
Chips Select
Serial Data Out
+5V
Reset DAC Registers
+
+5V
1µF
1
NC
VOUTA Sense
48
2
3
NC
VOUTA
47
SDI
AGND
46
4
DGND
VSS
45
5
CLK
VREFL AB Sense
44
6
DGND
VREFL AB
43
–10.000V
7
LDAC
VREFH AB
42
+10.000V
8
DGND
VREFH AB Sense
41
9
LOAD
VOUTB Sense
40
10
DGND
11
CS
12
DGND
13
SDO
14
15
16
DGND
17
RST
18
DGND
VOUTB
39
VOUTC Sense
38
DAC7734
VOUTC
37
VREFH CD Sense
36
DGND
VREFH CD
35
RSTSEL
VREFL CD
34
VREFL CD Sense
33
VOUTD Sense
32
VOUTD
31
30
19
NC
VSS
20
NC
VSS
29
21
DGND
AGND
28
22
DGND
AGND
27
23
VDD
VCC
26
24
VDD
VCC
25
–10V to +10V
–15V
–10V to +10V
–10V to +10V
+10.000V
–10.000V
–10V to +10V
–15V
0.1µF
0.1µF
0.1µF
+
+
1µF
1µF
+15V
NC = No Connection
FIGURE 3. Basic Dual-Supply Operation of the DAC7734.
ANALOG OUTPUTS
The DAC7734 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 (as shown in Figure 4), thus ensuring an accurate
output voltage.
When VSS = –15V (dual supply operation), the output
amplifier can swing to within 4V of the supply rails, guaranteed over the –40°C to +85°C temperature range. When
VSS = 0V (single-supply operation), and with RLOAD also
connected 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 amplifier has a negative offset. At the negative
limit of –5mV, the first specified output starts at code 0021H.
RW1
DAC7734
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 10V fullscale range has a 1LSB value of 152µV. With a load current
of 1mA, series wiring and connector resistance of only
150mΩ (RW2) will cause a voltage drop of 150µV, as shown
in Figure 4. To understand what this means in terms of a
system layout, the resistivity of a typical 1 ounce copperclad printed circuit board is 1/2 mΩ per square. For a 1mA
load, a 20 milli-inch wide printed circuit conductor 6 inches
long will result in a voltage drop of 150µV.
VOUTA Sense
48
VOUTA
47
AGND
46
VSS
45
VREFL AB Sense
44
VREFL AB
43
VREFH AB
42
VREFH AB Sense
41
VOUTB Sense
40
VOUTB
39
RW2
VOUT
+V
+10V
RW1
RW2
VOUT
FIGURE 4. Analog Output Closed-Loop Configuration
(1/2 DAC7734). RW represents wiring resistances.
®
17
DAC7734
REFERENCE INPUTS
The reference inputs, VREFL and VREFH, can be any voltage
between VSS + 4V and VCC – 4V, 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 –14.25V to
–15.75V. The voltage on VSS sets several bias points within
the converter. If VSS is not in one of these two configurations, the bias values may be in error and proper operation
of the device is not guaranteed.
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 2.0mA. The reference input
appears as a varying load to the reference. The DAC7734
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
9 show different reference configurations, and the effect on
the linearity and differential linearity.
The analog supplies have to come up first. If VCC and VSS
don't come up together, then VSS should come up first. If the
power supplies for the reference come up first, then the VCC
and VSS supplies will be “powered from the reference via the
ESD protection diode”, see page 4.
+V
VOUTA Sense
48
VOUTA
47
AGND
46
VSS
45
VREFL AB Sense
44
VREFL AB
43
VREFH AB
42
VREFH AB Sense
41
VOUTB Sense
40
VOUTB
39
DAC7734
OPA2234
VOUT
100Ω
2200pF
–10V
–15V
–V
1000pF
+V
100Ω
1000pF
+10V
2200pF
VOUT
–V
FIGURE 5. Dual Supply Configuration-Buffered References, used for Dual Supply Performance (1/2 DAC7734).
+V
DAC7734
VOUTA Sense
48
VOUTA
47
AGND
46
VSS
45
VREFL AB Sense
44
VREFL AB
43
VREFH AB
42
VOUT
100Ω
500Ω
2200pF
OPA350
+0.050V
50Ω
+V
99.5kΩ
1000pF
VREFH AB Sense
41
VOUTB Sense
40
VOUTB
39
+10V
100Ω
OPA227
1000pF
2200pF
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 used for Single-Supply Performance Curves
(1/2 DAC7734).
®
DAC7734
18
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC B, 25°C)
LE (LSB)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
DLE (LSB)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
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)
LE (LSB)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
DLE (LSB)
DLE (LSB)
LE (LSB)
DLE (LSB)
LE (LSB)
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC A, 25°C)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Digital Input Code
Digital Input Code
FIGURE 7. Integral Linearity and Differential Linearity Error Curves for Figure 8.
+V
VOUTA Sense
48
VOUTA
47
AGND
46
VSS
45
VREFL AB Sense
44
VREFL AB
43
VREFH AB
42
VREFH AB Sense
41
VOUTB Sense
40
VOUTB
39
DAC7734
OPA2234
VOUT
100Ω
2200pF
–5V
–V
1000pF
+V
100Ω
1000pF
+5V
2200pF
VOUT
–V
FIGURE 8. Dual-Supply Buffered Reference with VREFL = –5V and VREFH = +5V (1/2 DAC7734).
®
19
DAC7734
VOUTA Sense
48
VOUTA
47
AGND
46
VSS
45
VREFL AB Sense
44
VREFL AB
43
VREFH AB
42
VREFH AB Sense
41
DAC7734
VOUT
+V
100Ω
OPA350
1000pF
VOUTB Sense
40
VOUTB
39
1kΩ
2200pF
0.05V
50Ω
100Ω
1000pF
99kΩ
+V
2200pF
OPA227
+5V
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 9. Single-Supply Buffered Reference with a Reference Low of 50mV and Reference High of +5V.
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC B, 25°C)
LE (LSB)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
DLE (LSB)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
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)
LE (LSB)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
DLE (LSB)
DLE (LSB)
LE (LSB)
DLE (LSB)
LE (LSB)
LINEARITY ERROR AND
DIFFERENTIAL LINEARITY ERROR vs CODE
(DAC A, 25°C)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0000H 2000H 4000H 6000H 8000H A000H C000H E000H FFFFH
Digital Input Code
Digital Input Code
FIGURE 10. Integral Linearity and Differential Linearity Error Curves for Figure 9.
®
DAC7734
20
DIGITAL INTERFACE
device, all of the DAC outputs can be updated simultaneously by the rising edge of LDAC. Additionally, it allows
the DAC input registers to be written to at any point, then the
DAC output voltages can be synchronously changed via a
trigger signal (LDAC).
Table I shows the basic control logic for the DAC7734. The
interface consists of a Signal Data Clock (CLK) input, Serial
Data (SDI), DAC Input Register Load Control Signal
(LOAD), and DAC Register Load Control Signal (LDAC).
In addition, a Chip Select (CS) input is available to enable
serial communication when there are multiple serial devices.
An asynchronous Reset (RST) input, by the rising edge, is
provided to simplify start-up conditions, periodic resets, or
emergency resets to a known state, depending on the status
of the reset select (RSTSEL) signal.
Note that CS and CLK are combined with an OR gate, which
controls the serial-to-parallel shift register. These two inputs
are completely interchangeable. In addition, care must be
taken with the state of CLK when CS rises at the end of a
serial transfer. If CLK is LOW when CS rises, the OR gate
will provide a rising edge to the shift register, shifting the
internal data one additional bit. The result will be incorrect
data and possible selection of the wrong input register(s). If
both CS and CLK are used, CS should rise only when CLK
is HIGH. If not, then either CS or CLK can be used to
operate the shift register. See Table II for more information.
The DAC code, quick load control, and address are provided
via a 24-bit serial interface (see Table I). The first two bits
shifted into the shift register, B23 and B22, are the DAC
register address. These bits select the input register that will
be updated when LOAD goes LOW. The third bit, B21, is a
“Quick Load” bit such that if HIGH, the code in the shift
register is loaded into ALL DAC input registers when the
LOAD signal goes LOW, independent of the state of the
address bits, B23 and B22. If the “Quick Load” bit is LOW,
the contents of the shift register is loaded only to the DAC
register that is addressed. Bits B20 through B16 are not used
and can assume any logical value. The last sixteen bits, B15
through B0, make up the DAC code to be loaded into the
selected input register.
The internal DAC register is edge triggered and not level
triggered. When the LDAC signal is transitioned from LOW
to HIGH, the digital word currently in the DAC input
register is latched. The first set of registers (the DAC input
registers) are level triggered via the LOAD signal. This
double-buffered architecture has been designed so that new
data can be entered for each DAC without disturbing the
analog outputs. When the new data has been entered into the
CS(1)
CLK(1)
LOAD
RST
SERIAL SHIFT REGISTER
H(2)
X(3)
H
H
No Change
L(4)
L
H
H
No Change
L
↑(5)
H
H
Advanced One Bit
↑
L
H
H
Advanced One Bit
H(6)
X
L(7)
H
No Change
H(6)
X
H
↑(8)
No Change
NOTES: (1) CS and CLK are interchangeable. (2) H = Logic HIGH.
(3) X = Don’t Care. (4) L = Logic LOW (5) = Positive Logic Transition.
(6) A HIGH value is suggested in order to avoid a “false clock” from advancing
the shift register and changing the shift register. (7) If data is clocked into the
serial register while LOAD is LOW, the selected DAC register will change as
the shift register bits “flow” through A1 and A0. This will corrupt the data in
each DAC register that has been erroneously selected. (8) Rising edge of RST
causes no change in the contents of the serial shift register.
TABLE II. Serial Shift Register Truth Table.
SERIAL DATA INPUT
B23
A1
B22
B21
B20
B19
B18
B17
B16
B15
B14
B13
B12
B11
B10
B9
B8
B7
B6
B5
B4
B3
B2
B1
B0
A0
QUICK
LOAD
X
X
X
X
X
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
A1
A0
CS
RST
RSTSEL
LDAC
LOAD
INPUT
REGISTER
DAC
REGISTER
MODE
DAC
L
L
H
H
X
X
X
X
L
H
L
H
X
X
X
X
L
L
L
L
H
H
X
X
H
H
H
H
H
H
↑
↑
X
X
X
X
X
X
L
H
X
X
X
X
↑
H
X
X
L
L
L
L
H
H
X
X
Write
Write
Write
Write
Hold
Hold
Reset to Zero
Reset to Midscale
Hold
Hold
Hold
Hold
Write
Hold
Reset to Zero
Reset to Midscale
Write Input
Write Input
Write Input
Write Input
Update
Hold
Reset to Zero
Reset to Midscale
A
B
C
D
All
All
All
All
TABLE I. DAC7734 Logic Truth Table.
®
21
DAC7734
SERIAL-DATA OUTPUT
DIGITALLY-PROGRAMMABLE
CURRENT SOURCE
The Serial-Data Output (SDO) is the internal shift register's
output. For DAC7734, the SDO is a driven output and does
not require an external pull-up. Any number of DAC7734's
can be daisy chained by connecting the SDO pin of one
device to the SDI pin of the following device in the chain,
as shown in Figure 11.
The DAC7734 offers a unique set of features that allows a
wide range of flexibility in designing applications circuits
such as programmable current sources. The DAC7734 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 a transistor
to be placed within the loop to implement a digitallyprogrammable, unidirectional current source. The availability of a differential reference allows programmability for
both the full-scale and zero-scale currents. The output current is calculated as:
DIGITAL TIMING
Figure 12 and Table III provide detailed timing for the
digital interface of the DAC7734.
DIGITAL INPUT CODING
The DAC7734 input data is in Straight Binary format. The
output voltage is given by Equation 1.
  V H – VREF L   N  
I OUT =   REF

 • 
R SENSE
 65, 536  

where N is the digital input code. This equation does not
VOUT = VREF L +
(VREF H – VREF L) • N
65, 536
+ (VREF L / R SENSE )
(1)
include the effects of offset (zero-scale) or gain (full-scale)
errors.
LDAC
SCK
DAC7734
LDAC
DAC7734
LDAC
DAC7734
LDAC
CLK
CLK
CLK
DIN
SDI
CS
CS
SDO
LOAD
SDO
SDI
CS
LOAD
SDI
CS
SDO
LOAD
To
Other
Serial
Devices
LOAD
FIGURE 11. Daisy-Chaining DAC7734.
®
DAC7734
22
(2)
(LSB)
(MSB)
SDI
A0
A1
QUICK
LOAD
XXXXX
D15
D14
D3
D13
D1
D2
D0
CLK
tcss
tCSH
tLD1
tLD2
CS
tLDDD
LOAD
tLDRW
LDAC
tDS
tDH
SDI
tSDO
tCL
tCH
CLK
SDO
tLDDL
tLDDH
LDAC
tS
tS
±0.003%
ERROR BAND
VOUT
tRSTL
±0.003%
ERROR BAND
tRSTH
RESET
tRSSH
tRSSS
RESETSEL
FIGURE 12. Digital Input and Output Timing.
SYMBOL
DESCRIPTION
MIN
tDS
tDH
tCH
tCL
tCSS
tCSH
tLD1
tLD2
tLDRW
tLDDWL
tLDDH
tSDO
tRSSS
tRSSH
t RSTL
tRSTH
tLDDD
tS
Data Valid to CLK Rising
Data Held Valid after CLK Rises
CLK HIGH
CLK LOW
CS LOW to CLK Rising
CLK HIGH to CS Rising
LOAD HIGH to CLK Rising
CLK Rising to LOAD LOW
LOAD LOW Time
LDAC LOW Time
LDAC HIGH Time
SDO Propagation Delay
RESETSEL Valid to RESET HIGH
RESET HIGH to RESETSEL Not Valid
RESET LOW Time
RESET HIGH Time
LOAD LOW to LDAC Rising Time
Settling Time
10
20
25
25
15
0
10
30
30
40
40
10
0
100
10
10
40
MAX
45
10 (dual)/11(single)
UNITS
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
µs
TABLE III. Timing Specifications (TA = –40°C to +85°C).
®
23
DAC7734
Figure 13 shows a DAC7734 in a 4mA to 20mA current
output configuration. The output current can be determined
by Equation 3:
(3)
  5V – 1V   N    1V 
•
I OUT = 
 +
  250Ω   65, 536    250Ω 
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 (1V/250Ω).
IOUT
VPROGRAMMED
RSENSE
250Ω
VOUTA Sense
48
VOUTA
47
AGND
46
VSS
45
VREFL AB Sense
44
VREFL AB
43
VREFH AB
42
VREFH AB Sense
41
VOUTB Sense
40
VOUTB
39
DAC7734
+V
OPA2350
2200pF
100Ω
20kΩ
1.0V
+V
80kΩ
1000pF
5V
100Ω
1000pF
2200pF
IOUT
VPROGRAMMED
RSENSE
250Ω
FIGURE 13. 4-to-20mA Digitally Controlled Current Source (1/2 DAC7734).
®
DAC7734
24