Current-sense amplifier for precision shunt monitoring
The Texas Instruments INA293B2IDBVT is a dedicated current-sense amplifier in a SOT-23-5 package, designed to measure voltage across a shunt resistor on either the high side or low side of a supply rail. It integrates precision gain-setting resistors and a wide input common-mode range that extends from the negative supply to the positive rail, making it suitable for 5 V, 12 V, and 24 V systems.
The supply span from 2.7 V to 20 V covers 3.3 V logic rails, 5 V analog supplies, and 12 V/24 V industrial buses without an external regulator.
Input offset and bias — what they mean for measurement accuracy
The 15 µV input offset voltage is low enough that with a 10 mΩ shunt carrying 1 A, the offset contributes only 0.15% error before calibration. The 20 µA input bias current flows through the shunt and can introduce a small voltage drop — negligible with a 10 mΩ shunt (200 µV), but worth accounting for if the shunt resistance is higher. For a 100 mΩ shunt the bias drop becomes 2 mV, which may need a system-level trim.