Battery backup supervisor for volatile memory rails
It asserts a reset output (active-low, push-pull) and holds it for a minimum of 60 ms after the supply recovers, giving the processor time to stabilise before re-enabling the system. This part is designed for applications where a microcontroller or SRAM must retain state during a brief power loss — think RAID controllers, industrial PLCs, or any board with a coin-cell backup domain.
4.55 V threshold — where the switchover lands
On a nominal 5 V rail, the supervisor triggers the backup switchover before the rail drops below the minimum operating voltage of most 5 V logic, preventing brown-out corruption. On a 3.3 V system this part is not the right fit — the threshold would never be reached, so the backup never engages. The reset timeout of 60 ms minimum gives the main supply time to come up cleanly after a glitch. If your processor needs a longer hold time before release, you will need an external delay or a different supervisor with a programmable timeout.
Package and footprint for assembly planning
If your rework station or prototype run needs a tube, the TPS3619-50DGK (the tube variant) is the same die in the same package — just a different shipping medium.