Texas Instruments INA-DUAL-2AMP-EVM, User Manual

Page: 6 / 18

2.2.2 Buffered-Reference Voltage Connection
A buffered-reference 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
preserves common-mode rejection.
Figure 2-3 shows an example of how to set up the EVM for single-supply
operation with a buffered-reference voltage connection. Depending on the application, desirable single-supply
buffer operational amplifiers include the
OPA2330 and OPA2376 . The OPA2202 is a good choice for high-
voltage applications.
OUTA
INA-
INA+
VS- INB+
INB-
OUTB
VS+ 1
2
3
4 5
6
7
8
TP14
TP17
R17
0
R12
0
R13
GND GND
GND
GND
R19
C21
C18
C16
R11
V+
R8
R10
V-
V+
R21
R22
V-
GND
C15
V+
0.1µF
0
GND GND
R29
R26
R14
0
GND GND
R16
C20
TP15
TP3
GND
C14
OAV-
0.1µF
TP13
R7
GND
R6
C12
GND
C13
R15
R3
U1
VINA-
VINA+
RGA
RGA
1
2
3
4
U2
RefA
VOA
SenseA
V-
5
6
7
8
VINB-
VINB+
RGB
RGB
16
15
14
13
RefB
VOB
SenseB
V+
12
11
9
U3
GND
C22
V-
0.1µF
R32
GND
GND
GND GND
R38
C32
C30
C27 R31
V+
R30
V-
V+
R39
R40
V-
R35
R37
R33
R34
0
GND GND
R36
C31
TP21
C10
OAV+
0.1µF
GND
GND
TP19
TP16
GND
GND
C11
GND
GND
C19
R28
C29
TP20
TP22
0
0
R5
R25
C24
C17
R1
C5
R2
R9
R27
R23
C25 C26
R20
C28
R18
C23
R24
R4
TP10
TP18
VOB VOA
VINA-
VINA+
VINB-
VINB+
REFA
REFB
10
0
0
0
0
0
0
0 0
GND
GND
V-
V+
TP1
C1
10µF
C2
1µF
C6
10µF
C7
1µF
TP11
GND
OAV-
OAV+
TP2
C3
10µF
C4
1µF
C8
10µF
C9
1µF
TP12
J1 J2
Instrumentation Amplifier
Power Supply
Operational Amplifier Power
Supply
TP8 TP9 TP23 TP24 TP4 TP5 TP6 TP7
1
2
3
1
2
3
GND
GND
GND
OAVinA-
OAVinB-
Figure 2-3. Single-Supply Configuration, Buffered Reference Connection
Quick Start www.ti.com
6 INA-DUAL-2AMP-EVM SBOU272 – NOVEMBER 2021
Submit Document Feedback
Copyright © 2021 Texas Instruments Incorporated