Two-rail supervisor in a five-pin SOT
The MAX6419UK23-T is a multi-voltage supervisor from Analog Devices that monitors two supply rails and asserts an active-high reset when either drops below its threshold. It comes in a SOT-23-5 package — the same footprint as a small-signal transistor — and fits tight mixed-voltage boards where a second processor or an FPGA core rail needs its own watchdog.
What the dual-threshold setup means on the bench
One channel has a fixed 2.313 V threshold — typical for a 2.5 V logic rail — and the second channel is adjustable via an external resistor divider, so you set the trip point for a 1.8 V, 3.3 V, or any intermediate rail. The reset output is push-pull and active high, meaning it drives the reset line high on a fault and holds it there for an adjustable timeout period set by a capacitor. That capacitor-programmed delay lets you skip the glitch during power-up sequencing without adding a separate delay IC.
The SOT-23-5 package is one of the easiest to rework by hand — five pins, visible leads, no thermal pad underneath. A standard hot-air station at 300°C with a fine tip lifts the part cleanly without lifting adjacent pads.