DAC8801IDGK BURR-BROWN [Burr-Brown Corporation], DAC8801IDGK Datasheet - Page 10

• Manufacturer Part Number: DAC8801IDGK
• Description: 14-Bit, Serial Input Multiplying Digital-to-Analog Converter
• Manufacturer: BURR-BROWN [Burr-Brown Corporation]

DAC8801
SLAS403A – NOVEMBER 2004 – REVISED DECEMBER 2004
Stability Circuit
For a current-to-voltage design as shown in Figure 20, the DAC8801 current output (I
with the inverting node of the op amp should be as short as possible and according to correct PCB layout design.
For each code change there is a step function. If the GBP of the op amp is limited and parasitic capacitance is
excessive at the inverting node then gain peaking is possible. Therefore, for circuit stability, a compensation
capacitor C1 (4 pF to 20 pF typ) can be added to the design as shown in Figure 20.
Positive Voltage Output Circuit
As shown in Figure 21, in order to generate a positive voltage output, a negative reference is input to the
DAC8801. This design is suggested instead of using an inverting amp to invert the output due to tolerance errors
of the resistor. For a negative reference, V
a -2.5 V input to the DAC8801 with an op amp.
10
Figure 20. Gain Peaking Prevention Circuit With Compensation Capacitor
V
REF
OPA277
−
+
+2.5V Reference
Figure 21. Positive Voltage Output Circuit
V
V
OUT
REF
GND
V
V
DD
DD
−2.5 V
APPLICATION INFORMATION
GND
OUT
V
V
U1
IN
REF
R
and GND of the reference are level-shifted to a virtual ground and
V
FB
DD
V
DAC8801
DD
I
OUT
GND
R
FB
I
OUT
C1
C1
_
+
OPA277
−
+
0 3 V
U2
OUT
3 +2.5 V
V
OUT
V
OUT
OUT
) and the connection
www.ti.com