INA157
BUF634 inside feedback
loop contributes no error.
INA157
6kΩ
12kΩ
2
5
6
2
3
5
6
–In
+In
BUF634
VO
V0 = 2V1 + V2
6kΩ
1
3
V1
V2
RL
12kΩ
1
(Low IQ mode)
FIGURE 4. Precision Summing Amplifier.
FIGURE 6. Boosting Output Current.
The difference amplifier is a highly versatile building
block that is useful in a wide variety of applications. See
the INA105 data sheet for additional applications ideas,
including:
V1
INA157
–In
A1
2
5
6
• Current Receiver with Compliance to Rails
• ±10V Precision Voltage Reference
• ±5V Precision Voltage Reference
R2
R1
VO
R2
• Precision Average Value Amplifier
• Precision Bipolar Offsetting
1
3
• Precision Summing Amplifier with Gain
• Instrumentation Amplifier Guard Drive Generator
• Precision Summing Instrumentation Amplifier
• Precision Absolute Value Buffer
A2
V2
+In
VO = (1 + 2R2/R1) (V2 –V1)
• Precision Voltage-to-Current Converter with Differential
Inputs
The INA157 can be combined with op amps to form a complete instru-
mentation amplifier with specialized performance characteristics. Burr-
Brown offers many complete high performance IAs. Products with related
performances are shown at the right.
• Differential Input Voltage-to-Current Converter for Low
IOUT
• Isolating Current Source
SIMILIAR COMPLETE
BURR-BROWN IAs
• Differential Output Difference Amplifier
A1, A2
FEATURE
• Isolating Current Source with Buffering Amplifier for
Greater Accuracy
OPA227
OPA129
OPA277
OPA2134
Low Noise
INA103
INA116
INA114, INA128
INA111, INA121
Ultra Low Bias Current (fA)
Low Offset Drift, Low Noise
FET Input (pA)
• Window Comparator with Window Span and Window
Center Inputs
• Precision Voltage-Controlled Current Source with Buff-
ered Differential Inputs and Gain
FIGURE 5. Precision Instrumentation Amplifier.
• Digitally Controlled Gain of ±1 Amplifier
®
8
INA157