Datasheet

Data Sheet AD5791
Rev. D | Page 25 of 28
Gain of Two Configuration
Figure 52 shows an output amplifier configured for a gain of
two. The gain is set by the internal matched 6.8 kΩ resistors,
which are exactly twice the DAC resistance, having the effect of
removing an offset from the input bias current of the external
amplifier. In this configuration, the output spans from 2 ×
V
REFN
− V
REFP
to V
REFP
. This configuration is used to generate a
bipolar output span from a single ended reference input with
V
REFN
= 0 V. For this mode of operation, the RBUF bit of the
control register must be cleared to Logic 0.
A1
6.8kΩ 6.8kΩ
R
1
R
FB
20-BIT
DAC
V
REFPS
V
REFPF
V
REFP
V
REFN
= 0V
V
REFNS
AD5791
1/2 AD8676
1/2 AD8676
V
REFNF
R
FB
INV
V
OUT
08964-053
10pF
AD8675,
ADA4898-1
V
OUT
Figure 52. Output Amplifier in Gain of Two Configuration