Datasheet

V =
OUT
- 5V
10 D´
IN
2
n
V =
OUT
- ´V
REF
D
IN
2
n
V
REF
´ ´Gain ´
R +R
1 2
R
1
R
2
R
1
V
REF
IN/
V OUT
REF
V
REF
EXT
DAC7568
DAC8168
DAC8568
10 Fm 0.1 Fm
R
1
10kW
3-Wire
SerialInterface
AV
DD
AV
DD
+6V
±5V
-6V
OPA703
R
2
10kW
V
OUT
GND
+6V
±2.5V
-6V
OPA703
150nF
R
1
10kW
R
2
10kW
V
OUT
AV
DD
AV
DD
V
REF
IN/
V OUT
REF
DAC7568
DAC8168
DAC8568
3-Wire
SerialInterface
GND
DAC7568
DAC8168
DAC8568
SBAS430D –JANUARY 2009–REVISED MAY 2012 www.ti.com
BIPOLAR OPERATION USING THE D
IN
= decimal equivalent of the binary code that
DAC7568/DAC8168/DAC8568 is loaded to the DAC register. It can range from 0
to 4095 for DAC7568 (12 bit), 0 to 16,383 for
The DAC7568, DAC8168, and DAC8568 are
DAC8168 (14 bit), and 0 to 65535 for DAC8568
designed for single-supply operation, but a bipolar
(16 bit).
output range is also possible using the circuit in either
n = resolution in bits; either 12 (DAC7568), 14
Figure 127 or Figure 128. The circuit shown gives an
(DAC8168) or 16 (DAC8568)
output voltage range of ±V
REF
. Rail-to-rail operation at
Gain = 1 for A/B grades or 2 for C/D grades.
the amplifier output is achievable using an OPA703
as the output amplifier.
With V
REF
IN/V
REF
OUT = 5V, R
1
= R
2
= 10kΩ, for
grades A and B.
The output voltage for any input code can be
calculated with Equation 4:
(5)
This result has an output voltage range of ±5V with
0000h corresponding to a –5V output and FFFFh
(4)
corresponding to a +5V output for the 16-bit
Where:
DAC8568, as shown in Figure 127. Similarly, using
the internal reference, a ±2.5V output voltage range
can be achieved, as Figure 128 shows.
Figure 127. Bipolar Output Range Using External Reference at 5V
Figure 128. Bipolar Output Range Using Internal Reference
50 Submit Documentation Feedback Copyright © 2009–2012, Texas Instruments Incorporated
Product Folder Link(s): DAC7568 DAC8168 DAC8568