DESCRIPTION

The DS1250 4096k Nonvolatile SRAMs are 4,194,304-bit, fully static, nonvolatile SRAMs organized as 524,288 words by 8 bits. Each complete NV SRAM has a self-contained lithium energy source and control circuitry which constantly monitors VCC for an out-of-tolerance condition. When such a condition occurs, the lithium energy source is automatically switched on and write protection is unconditionally enabled to prevent data corruption. DIP-package DS1250 devices can be used in place of existing 512k x 8 static RAMs directly conforming to the popular byte-wide 32-pin DIP standard. DS1250 devices in the PowerCap Module package are directly surface mountable and are normally paired with a DS9034PC PowerCap to form a complete Nonvolatile SRAM module. There is no limit on the number of write cycles that can be executed and no additional support circuitry is required for microprocessor interfacing.

FEATURES

■ 10 years minimum data retention in the

absence of external power

■ Data is automatically protected during power loss

■ Replaces 512k x 8 volatile static RAM, EEPROM or Flash memory

■ Unlimited write cycles

■ Low-power CMOS

■ Read and write access times of 70ns

■ Lithium energy source is electrically

disconnected to retain freshness until power is

applied for the first time

■ Full ±10 VCC operating range (DS1250Y)

■ Optional ±5 VCC operating range (DS1250AB)

■ Optional industrial temperature range of

-40°C to +85°C, designated IND

■ JEDEC standard 32-pin DIP package

■ PowerCap Module (PCM) package

- Directly surface-mountable module

- Replaceable snap-on PowerCap provides lithium backup battery

- Standardized pinout for all nonvolatile SRAM products

- Detachment feature on PCM allows easy removal using a regular screwdriver