Battery backup supervisor for 5V rails
The Texas Instruments TPS3618-50DGKRG4 is a battery backup circuit that monitors a single 5V supply rail with a 4.55V threshold. When the monitored voltage drops below that threshold, it asserts an active-low reset output—push-pull, totem pole style—and holds it for a minimum of 60ms after the supply recovers. This gives downstream processors and logic time to stabilize before the reset releases.
What the 4.55V threshold means for your 5V system
The 4.55V threshold is set for a nominal 5V supply—it trips before the rail falls below the minimum operating voltage of most 5V logic and MCUs. If your system runs at 3.3V or uses a 5V rail that dips below 4.55V during normal operation (e.g., heavily loaded or long cable runs), this part will trigger nuisance resets. The 60ms minimum reset timeout gives a typical processor enough time to complete its power-on reset sequence, but check your processor's required reset pulse width against the datasheet's min/max specs.
The 8-VSSOP package (3.00mm width) is a small surface-mount footprint that fits on tight PCB layouts, but the 0.65mm pitch demands careful soldering profile control.
No official successor part is listed on the TI product page. For new designs, look at TI's current-generation supervisor family (e.g., TPS3808 or TPS382x series) with similar threshold and reset options—but verify pin compatibility and timeout specs against your board.