Current sense amp with 3 µV offset — what that buys you
The Texas Instruments INA186A4IDDFT is a zero-drift current-sense amplifier in a TSOT-23-8 package. It is built for low-side shunt measurements where you need to resolve microvolt-level drops across the sense resistor. The 3 µV input offset means you can use a smaller shunt value and still keep the measurement error under a few percent — handy when you are trying to minimise power dissipation in the sense path. Supply current sits at 48 µA, so it can run continuously off a battery rail without draining it. The 45 kHz gain-bandwidth product is enough for DC load monitoring and low-speed overcurrent detection; it is not built for fast-switching converter loops.
The output is rail-to-rail, so you get the full ADC input range even at low supply voltages.
Package and mounting
Comes in a TSOT-23-8 package — surface-mount, small footprint, easy to hand-solder with a fine tip if you are doing rework. No exposed pad to worry about, so the layout is straightforward: decouple close to the supply pin, keep the sense traces short and matched. The input bias current is 500 pA, so you can use a high-value shunt without loading the measurement.