1225

www.DataSheet4U.com DS1225AB/AD 64k Nonvolatile SRAM www.dalsemi.com 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 PIN ASSIGNMENT NC A12 A7 A6 A5 A4 A3 A2 A1 A0 DQ0 DQ1 DQ2 GND 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 VCC WE NC A8 A9 A11 OE A10 CE DQ7 DQ6 DQ5 DQ4 DQ3 28-Pin ENCAPSULATED PACKAGE 720-mil EXTENDED PIN DESCRIPTION A0-A12 DQ0-DQ7 CE WE OE VCC GND NC - Address Inputs - Data In/Data Out - Chip Enable - Write Enable - Output Enable - Power (+5V) - Ground - No Connect DESCRIPTION The DS1225AB and DS1225AD are 65,536-bit, fully static, nonvolatile SRAMs organized as 8192 words by 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 ...