DS1225AD

Features:

10 years minimum data retention in the absence of external power
Data is automatically protected during power loss
Directly replaces 8k x 8 volatile static RAM or EEPROM
Unlimited write cycles
Low-power CMOS
JEDEC standard 28-pin DIP package
Read and write access times as fast as 70 ns
Lithium energy source is electrically disconnected to retain freshness until power is applied for the first time
Full ±10% VCC operating range (DS1225AD)
Optional ±5% VCC operating range (DS1225AB)
Optional industrial temperature range of -40°C to +85°C, designated IND


Pinout




Specifications

Voltage on Any Pin Relative to Ground                                                          -0.3V to +7.0V
Operating Temperature                               0°C to 70°C; -40°C to +85°C for IND parts
Storage Temperature                             -40°C to +70°C; -40°C to +85°C for IND parts
Soldering Temperature                                                                     260°C for 10 seconds 


Description

The DS1225AB and DS1225AD are 65,536-bit, fully static, nonvolatile SRAMs organized as 8192 wordsby 8 bits. Each 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. The NV SRAMs can be used in place of existing 8k x 8 SRAMs directly conforming to the popular bytewide 28-pin DIP standard. The DS1225AB and DS1225AD  also match the pinout of the 2764 EPROM and the 2864 EEPROM, allowing direct substitution while enhancing performance. There is no limit on the
number of write cycles that can be executed and no additional support circuitry is required for microprocessor inter-facing.