INA351 Tiny Low-Power Instrumentation Amp

Texas Instruments' INA351 is a selectable-gain instrumentation amp with an integrated reference buffer that offers four gain options in a small package. The INA351ABS has gain options of 10 or 20, which are selected by toggling the gain select (GS) pin. The amp is an excellent choice for bridge-type sensing and differential-to-single-ended conversion applications. Built with precision-matched integrated resistors, the amp saves on BOM costs, pick-and-place machine handling costs, and board space by removing the need for precise or closely-matched external resistors.

The INA351 can interface directly to low-speed 10-bit to 14-bit analog-to-digital converters (ADCs) and is ideal for replacing the discrete implementation of instrumentation amps that are built with commodity amps and discrete resistors. Designed with a three-amp architecture, the device is optimized for delivering performance, achieving 86 dB of minimum CMRR and an accurate maximum gain-error of 0.1%, as well as a maximum offset of 1.3 mV across all gain options while consuming a maximum quiescent current of 135 µA. The integrated shutdown option can turn the amp off when idle, providing additional power savings for battery-powered applications.