[Simtek]

DESCRIPTION
The Simtek STK22C48 is a fast static RAM with a nonvolatile 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 Nonvolatile Elements. Data transfers from the SRAM to the Nonvolatile Elements (the STORE operation) can take place automatically on power down. A 68µF or larger capacitor tied from VCAP to ground guarantees the STORE operation, regardless of power-down slew rate or loss of power from “hot swapping”. Transfers from the Nonvolatile Elements to the SRAM (the RECALL operation) take place automatically on restoration of power. A hardware STORE may be initiated with the HSB pin.

FEATURES
• 25ns, 35ns and 45ns Access Times
• “Hands-off” Automatic STORE with External 68µF Capacitor on Power Down
• STORE to Nonvolatile Elements Initiated by Hardware or AutoStore™ on Power Down
• Automatic RECALL on Power Up
• 10mA Typical ICC at 200ns Cycle Time
• Unlimited READ, WRITE and RECALL Cycles
• 1,000,000 STORE Cycles to Nonvolatile Elements
• 100-Year Data Retention in Nonvolatile Elements
• Single 5V + 10% Operation
• Commercial and Industrial Temperatures
• 28-Pin DIP and SOIC Packages