3V supervisor in a SOT-23-3 — what it does and where it fits
The Maxim Integrated MAX6328UR30+T is a single-channel voltage supervisor that monitors a 3V supply rail and holds the reset output low for a minimum of 100ms after the voltage rises above the threshold. The open-drain, active-low output connects directly to the reset input of most MCUs, MPUs, or FPGAs without needing a level shifter. With the industrial temperature range of -40°C to +85°C, this part suits outdoor telecom gear, factory automation controllers, and power-supply sequencing circuits where a compact SOT-23-3 footprint matters.
Threshold and timeout — the two numbers that decide fit
The 3V threshold is the trip point at which the supervisor asserts reset. If your processor runs on a 3.3V rail, this part triggers when the supply drops to 3V — that gives 300mV of headroom before the core loses logic state, which is tight but workable for a cleanly regulated rail. For a 3.0V rail, the threshold is effectively the supply itself, so the supervisor holds reset until the rail is fully up. The 100ms minimum reset timeout holds the processor off long enough for the oscillator to stabilise and the supply to settle after power-up or a brown-out event. If your processor needs a longer reset pulse, you add an external RC delay on the output — the open-drain output makes that straightforward.
Lifecycle and sourcing — active, no LTB watch needed
ROHS3 compliant. For BOM-line planning, this part is a safe choice for new designs and ongoing production — no last-time-buy risk to schedule around.