The MAX4173FEUT is a single-channel current-sense amplifier from Maxim Integrated, designed to monitor current by amplifying the voltage drop across an external shunt resistor. It integrates the gain-setting resistors internally, so the output voltage is proportional to the sensed current with a fixed gain. The part is specified for a supply span from 3 V to 28 V, making it compatible with common industrial and telecom rails such as 5 V, 12 V, and 24 V. The -3 dB bandwidth is 1.4 MHz, which means it can track load transients in the tens-of-microseconds range — adequate for overcurrent detection and average-current monitoring in motor drives, power supplies, and battery-management systems. The input offset voltage is 300 µV, and the quiescent supply current is 420 µA.
The 3 V to 28 V supply span is the headline selection parameter for this part. The 1.4 MHz bandwidth defines the fastest current step this amplifier can reproduce accurately. For a 100 kHz switching power supply, the average output current is captured cleanly, but the switching ripple itself will be attenuated. If you need to see sub-microsecond current spikes (e.g., in a GaN-based converter), a part with 10 MHz or higher bandwidth would be needed. The 300 µV input offset sets the minimum resolvable shunt voltage — with a 10 mΩ shunt, that offset corresponds to 30 mA of DC error, which is acceptable for most load-monitoring applications but may be too high for precision battery-charge counting.
Temperature grade and environment
This part is not qualified to AEC-Q100, so it is not recommended for automotive under-hood or chassis applications where extended temperature or reliability screening is required. For indoor power supplies, motor drives, and battery-management boards, the industrial range is sufficient.