1 Features
• Fixed gain of 10V/V instrumentation amp with
configurable reference amp
• INA performance for 10-bit to 14-bit systems
– CMRR: 95 dB (typical)
– Gain error: 0.015% (typical)
– Bandwidth: 100 kHz (typical)
• Reference amp can be used for:
– External DC error calibration with servo loop
– Providing buffered voltage of external circuits
– Filtering or adjustment of reference voltage
• Ultra-small package option (2mm x 2mm)
• Drives 1 nF with under 10% overshoot (typical)
• Optimized quiescent current: 110 μA (typical)
• Supply range: 1.8 V (±0.9 V) to 5.5 V (±2.75 V)
• Specified temperature range: –40°C to 125°C

2 Applications
• Electrocardiogram
• Pressure transmitter
• Weigh scale
• Flow transmitter
• Wearable fitness and activity monitor
• Blood glucose monitor
• Temperature sensing with RTD

3 Description
INA351A is a fixed gain of 10 instrumentation
amplifier with a configurable reference amplifier in a
small package. This instrumentation amp (INA) is built
with precision-matched resistors to achieve excellent
CMRR and gain error performance in a small, lowcost
form factor. This makes INA351A a great solution
to replace discrete INA implementations to achieve
higher performance and more compact designs with
minimal impact to bill of materials (BOM) costs.
The integrated, configurable reference amplifier can
be used as a buffer for external use or as part
of a closed-loop calibration circuit to achieve better
DC precision. The closed-loop calibration can be
accomplished by implementing a servo loop amplifier
to calibrate DC errors from sensors (like offset, offset
drift and so forth) at the INA output when the INA
input signal is at a slightly higher frequency than DC
depending on the application.
INA351A achieves 86 dB of minimum CMRR, an
accurate 0.1% of maximum gain error and only
consumes a maximum of 135 μA quiescent current at
room temperature. The INA can directly drive sub-1
kHz, 10-bit to 14-bit, delta-sigma analog-to-digital
converters (ADC) without an ADC driver, making it
a great choice for portable, battery-powered medical
applications like electrocardiograms or wearable
health monitors.