What the 1.4 MHz bandwidth means for your current-sense path
The MAX4173FEUT+T is a single-channel current-sense amplifier from Analog Devices, in a SOT-23-6 package. Its 1.4 MHz -3dB bandwidth means it can track fast load transients and switching ripple in a buck converter or motor-drive phase current — the output settles fast enough for a downstream ADC sampling at 100 kSPS or a comparator triggering on an overcurrent threshold. Supply current is 420 µA typical, and the input offset voltage is 300 µV maximum — low enough to keep the shunt-voltage error under 1% for a 50 mV full-scale drop across the sense resistor. Input bias current is 700 µA, which flows through the sense resistor and adds a systematic offset; account for it in the measurement chain if the shunt value exceeds a few milliohms.
Packaged in a 6-lead SOT-23 (SOT-6 supplier device package), it mounts with standard surface-mount reflow profiles. The small footprint keeps the sense-resistor layout tight — the feedback path runs directly under the IC to minimise parasitic inductance between the shunt and the amplifier inputs.