Maxim Integrated DS1225AD
The DS1225AD provides full-functional capability for VCC greater than 4.5 volts and write protects by 4.25 volts. The nonvolatile static RAMs constantly monitor VCC.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 of 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 DS1225AB/AD 64k Nonvolatile SRAM PIN ASSIGNMENT NC A12 A7 A6 A5 A4 A3 A2 A1 A0 DQ0 DQ1 1 2 3 4 5 6 7 8 9 10 11 12 28 VCC 27 WE 26 NC 25 A8 24 A9 23 A11 22 OE 21 A10 20 CE 19 DQ7 18 DQ6 17 DQ5 DQ2 13 16 DQ4 GND 14 15 DQ3 28-Pin ENCAPSULATED PACKAGE 720-mil EXTENDED PIN
DESCRIPTION
A0-A12 - Address Inputs DQ0-DQ7 - Data In/Data Out CE - Chip Enable WE - Write Enable OE VCC GND NC - Output Enable - Power (+5V) - Ground - No ConnectDESCRIPTION
The DS1225AB and DS1225AD are 65,536-bit, fully static, nonvolatile SRAMs organized as 8192 words by 8 bits.