Datasheet

±IN
R
G
INA827
R
G
+IN
+V
S
V
OUT
REF
±V
S
V+
VO
U1
+
1
2
U2
3
4
8
7
6
5
10 PF
0.1 PF
10 PF 0.1 PF
OAV+
10 PF
V±
RO
C10 C7
C12
C4
0.1 PF
10 PF 0.1 PF
OAV±
C11
C5
C6C9
R3
OAVIN+
0 
+
R1
R2
V±IN
0 
0 
V+IN
Sine Wave
0.1 V
PP
+
±
5 V
+
±
5 V
0 
+
±
2.5 V
OPA376
Quick Start www.ti.com
Make the following connections to set up the INA827EVM for single-supply operation with a buffered
reference voltage. This example uses an OPA376 as the buffer operational amplifier. Depending on the
application, alternative single-supply buffer operational amplifiers include the OPA330 and OPA378. The
OPA277 is a good choice for high-voltage applications. A buffered configuration is useful when the source
impedance is high (for example, a voltage divider). Buffering a high-impedance source with an operational
amplifier provides a low-impedance source, and thus preserves common-mode rejection.
1. +5 V to V+ and OAV+ test points.
2. GND to V– and OAV– test points.
3. +2.5 V to OAVIN+ test point.
4. Populate R3 with a 0-Ω resistor.
5. Populate C4, C5, C11, and C12 with bypass capacitors.
6. Differential input (for example, a 0.1-V
PP
sine wave) to V–IN and V+IN test points.
7. Oscilloscope to VO test point.
Ensure that R1 = R2 = RO = 0 Ω and that R
G
, CO, R4, and R5 are not populated. Figure 5 depicts a
proper dual-supply configuration with a buffered REF voltage.
Figure 5. INA827EVM: Single-Supply Configuration, Buffered REF Connection
6
INA827EVM SBOU121–June 2012
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