Battery backup supervisor for volatile memory rails
The MAX16039PLA29+T is a battery backup circuit that monitors a single voltage rail and switches the load to a backup battery when the primary supply drops below 2.93 V — the threshold is factory-trimmed to that level, so no external resistor divider sets the trip point. When the monitored voltage falls below threshold, the reset output (Active Low, open-drain) asserts and holds for a minimum of 140 ms after the supply recovers, giving the downstream processor time to stabilize before it releases the reset line. Housed in an 8-uDFN (2x2 mm) package, the part fits into compact battery-backed SRAM or RTC circuits where board space is tight and the backup switchover must be glitch-free.