The bq4847 Real-Time Clock Module is a low-power microprocessor peripheral that integrates a time-of-day clock, a 100-year calendar, a CPU supervisor, a battery, and a crystal in a 28-pin DIP module. The part is ideal for fax machines, copiers, industrial control systems, point-of-sale terminals, data loggers, and computers.

The bq4847 contains an internal battery and crystal. Through the use of the conditional chip enable output (CE\_OUT) and battery voltage output (V_OUT) pins, the bq4847 can write-protect and make nonvolatile an external SRAM. The backup cell powers the real-time clock and maintains SRAM information in the absence of system voltage.

The bq4847 contains a temperature-compensated reference and comparator circuit that monitors the status of its voltage supply.