1.8V rail watchdog with 619ms hold-up
The TPS3840DL18DBVR is a single-channel power supply monitor from Texas Instruments, designed to assert a reset signal when the monitored 1.8V rail drops below the threshold. The active-low, open-drain output stays low for a typical 619ms after the rail returns — long enough for downstream regulators and MCUs to finish their power-up sequence before the system starts executing code.
Industrial temp range and package fit
The SOT-23-5 package (SC-74A footprint) is a standard 5-pin surface-mount layout — the same footprint used by many other voltage supervisors, making it a straightforward drop-in for existing BOM positions.
For new designs or production replenishment, the part is sourced per RFQ — no minimum buy or LTB math needed.