Active current-sense amp in a rework-friendly SOT-23-5
It monitors current via an external shunt resistor and outputs a rail-to-rail voltage proportional to the sensed current. Its 350 kHz bandwidth and 2V/µs slew rate suit it for monitoring DC motor phases, solenoid currents, and power-supply rails where moderate bandwidth is sufficient.
The 350 kHz -3 dB bandwidth sets the upper frequency for accurate current measurement. The 2V/µs slew rate limits the amplifier's ability to track fast current transients — expect about 2 µs to swing from 0.5 V to 4.5 V. If you need sub-microsecond response to a short-circuit event, a faster current-sense amp (e.g., with 5 V/µs or more) is a better fit.
Supply range and input offset — design margin
The INA180B3IDBVT operates from 2.7 V to 5.5 V single supply, covering common 3.3 V and 5 V rails. Input offset voltage is 100 µV typical — for a 10 mΩ shunt, that translates to a 10 A offset error. The 80 µA input bias current flows into the shunt; with a 1 kΩ shunt, it adds 80 mV of offset, so keep shunt resistance low (sub-100 mΩ) to minimise bias-induced error.
Package and rework — SOT-23-5 is hand-solderable
The SOT-23-5 package (SC-74A body) has a 0.95 mm pin pitch and visible pin 1 mark (beveled corner). It reflows cleanly with a standard hot-air station at 300°C for 10–15 seconds.
It is RoHS3 compliant and free of the six restricted substances plus four phthalates.