DAC702 BURR-BROWN [Burr-Brown Corporation], DAC702 Datasheet - Page 10

• Manufacturer Part Number: DAC702
• Description: Monolithic 16-Bit DIGITAL-TO-ANALOG CONVERTERS
• Manufacturer: BURR-BROWN [Burr-Brown Corporation]

APPLICATIONS
DRIVING AN EXTERNAL OP AMP
WITH CURRENT OUTPUT D/AS
DAC702 is current output devices and will drive the sum-
ming junction of an op amp to produce an output voltage as
shown in Figure 9. Use of the internal feedback resistor is
required to obtain specified gain accuracy and low gain drift.
DAC702 can be scaled for any desired voltage range with an
external feedback resistor, but at the expense of increased
drifts of up to 50ppm/ C. The resistors in the DAC702 ratio
track to 1ppm/ C but their absolute TCR may be as high as
An alternative method of scaling the output voltage of the
D/A converter and preserving the low gain drift is shown in
Figure 10.
OUTPUTS LARGER THAN 20V RANGE
For output voltage ranges larger than 10V, a high voltage
op amp may be employed with an external feedback resistor.
Use I
–2mA for unipolar voltage ranges (see Figure 11). Use
protection diodes as shown when a high voltage op amp is
used.
50ppm/ C.
OUT
values of 1mA for bipolar voltage ranges and
®
DAC701, 702, 703
10
FIGURE 9. External Op Amp Using Internal Feedback
FIGURE 11. External Op Amp Using External Feedback
FIGURE 10. External Op Amp Using Internal and External
5k
0 to
2mA
R
0 to
2mA
F
5k
0 to
2mA
Feedback Resistors to Maintain Low Gain Drift.
Resistors.
Resistors.
4k
4k
R
F
Common
4k
R
I
F
Common
OUT
I
OUT
*
R
1
, R
2
TCR < ±10ppm/°C
R
1
I
BB3584
*
R
F
R
2
*
V
OUT
V
OUT
V
OUT