What this supervisor does on your rail
The Maxim Integrated MAX6348UR40 is a single-channel voltage supervisor that monitors a 4V threshold rail and asserts an active-low reset when the supply drops below that level. The open-drain output stays low for a minimum of 100ms after the supply returns above threshold, giving the downstream processor or FPGA time to stabilize before release. This is a straightforward power-on reset part — no watchdog, no manual reset input, just the core supervisor function in a three-pin SOT-23-3 package.
Threshold and timeout — what they mean for your BOM
The 4V threshold monitors a 5V nominal rail. The 100ms minimum reset timeout covers most power-supply ramp-up and brown-out recovery sequences.
Open-drain output — wiring and level translation
The open-drain output lets you pull the reset line to any voltage up to the absolute maximum of the pin, independent of the supervisor's supply.