The INA281 is a high-precision current sense amplifier that can measure voltage drops across shunt resistors over a wide common-mode range from –4 V to 110 V. The negative common-mode voltage allows the device to operate below ground, thus accommodating precise measurement of recirculating currents in half-bridge applications. The combination of a low offset voltage, small gain error and high DC CMRR enables highly accurate current measurement. The INA281 is not only designed for DC current measurement, but also for high-speed applications (like fast overcurrent protection, for example) with a high bandwidth of 1.3 MHz and an 65-dB AC CMRR (at 50 kHz).
The INA281 operates from a single 2.7-V to 20-V supply, drawing 1.5 mA of supply current. The INA281 is available with five gain options: 20 V/V, 50 V/V, 100 V/V, 200 V/V, and 500 V/V. These gain options address wide dynamic range for current-sensing applications.
The INA281 is specified over an operating temperature range of −40 °C to +125 °C and is offered in a space-saving SOT-23 package with two pin-out variants.