[Simtek]

DESCRIPTION
The STK25C48 is a fast SRAM with a nonvolatile EEPROM element incorporated in each static memory cell. The SRAM can be read and written an unlimited number of times, while independent nonvolatile data resides in the EEPROM. Data transfers from the SRAM to the EEPROM (the STORE operation) can take place automatically on power down using charge stored in system capacitance. Transfers from the EEPROM to the SRAM (the RECALL operation) take place automatically on restoration of power. The nvSRAM can be used in place of existing 2K x 8 SRAMs and also matches the pinout of 2K x 8 battery-backed SRAMs, EPROMs and EEPROMs, allowing direct substitution while enhancing performance. There is no limit on the number of read or write cycles that can be executed, and no support circuitry is required for microprocessor interfacing.

FEATURES
• Nonvolatile Storage without Battery Problems
• Directly Replaces 2K x 8 Static RAM, Battery Backed RAM or EEPROM
• 20ns, 25ns, 35ns and 45ns Access Times
• STORE to EEPROM Initiated by AutoStore™ on Power Down
• RECALL to SRAM Initiated by Software or Power Restore
• 10mA Typical ICC at 200ns Cycle Time
• Unlimited READ, WRITE and RECALL Cycles
• 1,000,000 STORE Cycles to EEPROM
• 100-Year Data Retention over Full Industrial Temperature Range
• Commercial and Industrial Temperatures
• 24-Pin 600 PDIP Package