The STMicroelectronics STM810LWX6F is a simple reset/power-on reset IC that monitors a single voltage rail and asserts a reset signal when the supply drops below its 4.63V threshold. It holds reset active for a minimum of 140ms after the rail recovers, giving the processor time to stabilize its internal state before code execution starts. The active-high, push-pull output connects directly to a microcontroller's reset input without needing an external pull-up resistor. This part is commonly used in 5V systems — industrial controllers, telecom line cards, and embedded instrumentation — where a clean, deterministic power-on sequence is required.
140ms reset timeout — why the window matters
The 140ms minimum reset timeout is the interval the supervisor holds the processor in reset after the monitored rail rises above the 4.63V threshold. This delay lets the oscillator start, the PLL lock, and the internal voltage regulators settle before the first instruction fetch. A timeout that is too short can cause the processor to boot into an undefined state if the rail has not fully stabilized. The 140ms figure is a minimum — actual timeout may be longer, but the design must guarantee at least 140ms of reset assertion after a valid power-on event.
The active status is confirmed by the manufacturer's current lifecycle designation.
This is a current-production part available through independent distribution. The SOT-23-3 footprint is standard and shared with many other supervisor ICs, so board layout changes are minimal if a second source is needed.