DESCRIPTION
The DS1312 Nonvolatile Controller with Battery Monitor is a CMOS circuit which solves the application problem of converting CMOS RAM into nonvolatile memory. Incoming power is monitored for an outof-tolerance condition. When such a condition is detected, chip enable is inhibited to accomplish write protection and the battery is switched on to supply the RAM with uninterrupted power. Special circuitry uses a low-leakage CMOS process which affords precise voltage detection at extremely low battery consumption.

FEATURES
◾ Converts CMOS SRAM into nonvolatile memory
◾ Unconditionally write-protects SRAM when VCC is out of tolerance
◾ Automatically switches to battery backup supply when VCC power failure occurs
◾ Monitors voltage of a lithium cell and provides advanced warning of impending battery failure
◾ Signals low-battery condition on active low Battery Warning output signal
◾ Optional 5% or 10% power-fail detection
◾ Space-saving 8-pin DIP and SOIC packages
◾ Optional 16-pin SOIC and 20-pin TSSOP versions reset processor when power failure occurs and hold processor in reset during system power-up
◾ Industrial temperature range of -40°C to +85°C