2.625V threshold, 150 ms timeout — the fit for a 2.5V rail supervisor
The MAX6866UK26D3L+: The active-low, open-drain output asserts reset when the monitored supply drops below that threshold and holds it low for a minimum of 150 ms after the rail recovers — long enough for the downstream processor's oscillator and PLL to stabilise before code execution starts. The open-drain output allows wired-OR connection with other reset sources, and the pull-up resistor is external — choose a value that keeps the rise time within the processor's reset input spec.
Nanopower quiescent — why the series name matters for battery life
The nanopower series is built for always-on monitoring where the supervisor's own draw must not compete with the system's sleep current. Typical quiescent current for the nanopower family is in the sub-1 µA range — the exact figure for this variant is in the datasheet, but the series branding signals that the part is optimised for battery-powered or energy-harvesting designs where every microamp counts.
SOT-23-5 footprint and sourcing posture
Housed in the standard SOT-23-5 (SC-74A) package, the MAX6866UK26D3L+ shares the same 5-pin footprint as many other supervisory ICs — the layout is straightforward and the part is a drop-in for existing designs that use a 2.625V threshold supervisor in this package.