80 kHz bandwidth, 0.5 µV offset — the measurement floor for precision current sensing
The MAX40201FAUA+ is a dual-channel current-sense amplifier from Analog Devices, built to measure current through an external shunt resistor with a 0.5 µV typical input offset voltage and 80 kHz of -3 dB bandwidth. The 0.5 µV offset means the amplifier resolves a 50 mV full-scale shunt drop with 0.001% error before the noise floor — the measurement floor is set by the shunt's own thermal EMF, not the amplifier. The 80 kHz bandwidth supports monitoring fast load transients in switching regulators or motor phases — the output settles within a few microseconds of a current step, so the downstream ADC or comparator sees the real event, not a filtered version.
Dual channel, 1.3 mA supply per pair — power budget for multi-rail systems
The 200 nA input bias current sets the minimum practical shunt value — a 10 mΩ shunt develops 2 µV of offset from bias alone, which is four times the amplifier's own offset and becomes the dominant error term below 10 mΩ.