What the STM6823LWY6F is and what it does
It uses an active-low, push-pull output, so it pulls the reset line low during a fault and drives it high when the rail is valid — no external pull-up resistor needed. The reset timeout is a minimum of 140 ms, which gives the system power supply and oscillator time to stabilise before the processor starts executing code.
The voltage threshold is 4.63 V, which means this part is designed to monitor a 5 V supply rail. It will assert reset when the rail drops to about 4.63 V or below, and de-assert (release) once the rail recovers above that level plus a small hysteresis. If your design uses a 3.3 V or 1.8 V rail, this part won't work — you need a supervisor with a lower threshold.
Package and rework — SOT-23-5
Housed in a SOT-23-5 package (SC-74A, SOT-753), surface-mount only. Five pins, fine-pitch enough that a steady hand and a hot-air station will lift it clean without lifting the pads. The small thermal mass means it reflows quickly; just don't cook it past 260°C peak for more than 10 seconds.
Lifecycle and sourcing
ROHS3 compliant.