Texas Instruments BQ2201SN-N, Battery Charge Controller IC, 5 V 8-Pin, SOIC

The Texas offers a BQ series of non-volatile controller unit provides all necessary functions for converting a standard CMOS sram into non-volatile read or write memory. A precision comparator monitors the 5V vcc input for an out-of-tolerance condition.

Write protect control
3-volt primary cell inputs
Power monitoring and switching for 3-volt battery-backup applications