Four-rail supervisor for multi-voltage boards
The Maxim Integrated MAX6888METE is a four-channel multi-voltage supervisor that monitors up to four supply rails simultaneously. It tracks fixed thresholds at 1.8 V, 2.5 V, and 3.3 V, plus one adjustable input for a custom voltage — covering the common core, I/O, and memory rails on a mixed-voltage PCB. The active-low reset output is open-drain, so it can be wire-ORed with other reset sources in the system.
The reset timeout is specified at 180 ms minimum. That is the guaranteed hold time the part keeps the reset line asserted after all monitored voltages rise above their thresholds. For a processor or FPGA, this gives the power supplies and oscillator time to stabilise before the core starts executing code. If the board has a fast-booting MCU or a power-good cascade, verify this 180 ms window fits the downstream device's reset-hold requirement — some parts expect a shorter or longer pulse.
It is a surface-mount part, so plan for reflow assembly and a thermal pad footprint in the layout.