Data Sheet
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 × VREFN −
VREFP to VREFP. This configuration is used to generate a bipolar
output span from a single-ended reference input, with VREFN =
0 V. For this mode of operation, the RBUF bit of the control
register must be cleared to Logic 0.
AD5781
VREFP
1/2 AD8676
VREFPF
VREFPS
A1
18-BIT
DAC
R1 RFB RFB
6.8kΩ 6.8kΩ
INV
VOUT
VREFNF
1/2 AD8676
VREFNS
AD5781
10pF
VOUT
AD8675,
ADA4898-1,
ADA4004-1
VREFN = 0V
Figure 52. Output Amplifier in Gain of Two Configuration
Rev. D | Page 25 of 28