Non-Volatile SRAM Harbors Y2K-Compliant Real-Time Clock

An ultra low-power 8k x 8 SRAM array, a long-life lithium coin cell, a quartz crystal, power-fail control circuitry and a Y2K-compatible real-time clock are all contained within the M48T559Y Snaphat device. Said to offer the world's smallest footprint for its functions, the non-volatile device provides fast SRAM access, with the clock/calendar functions maintained within the upper 16 bytes of the SRAM array. It also offers a watchdog timer, an alarm with wake-up in battery backup mode, and a battery-low warning.The SRAM array uses four-transistor SRAM cells to achieve higher performance, reduced cost and lower standby power draw. Integral power-fail circuitry monitors the VCC line for out-of-tolerance conditions and automatically switches to the coin cell should one occur. At that time, the chip is switched to its write-protected mode, eliminating the chance of spurious write cycles. The module's Snaphat battery/crystal allows for replacement of the coin cell.