DS1230W Datasheet | Dallas

FEATURES 10 years minimum data retention in the absence of external power Data is automatically protected during power loss Replaces 32k x 8 volatile static RAM, EEPROM or Flash memory Unlimited write cycles Low-power CMOS Read and write access times as fast as 150 ns Lithium energy source is electrically disconnected to retain freshness until power is applied for the first time Optional industrial temperature range of -40°C to +85°C, designated IND JEDEC standard 28-pin DIP package New Power Cap Module (PCM) package - Directly surface-mountable module - Replaceable snap-on Power Cap provides lithium backup battery - Standardized pinout for all nonvolatile SRAM products - Detachment feature on Power Cap allows easy removal using a regular screwdriver PIN ASSIGNMENT A14 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 A13 A8 A9 A11 OE A10 CE DQ7 DQ6 DQ5 DQ4 DQ3 28-Pin ENCAPSULATED PACKAGE 740-mil EXTENDED 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 NC NC A14 A13 A12 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0 NC NC NC NC VCC WE OE CE DQ7 DQ6 DQ5 DQ4 DQ3 DQ2 DQ1 DQ0 GND 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 GND VBAT 34-Pin POWERCAP MODULE (PCM) (USES DS9034PC POWERCAP) PIN DESCRIPTION A0 - A14 DQ0 - DQ7 CE WE OE VCC GND NC - Address Inputs - Data In/Data Out - Chip Enable - Write Enable - Output Enable - Power (+3.3V) - Ground - No Connect 1 of 11 DESCRIPTION The DS1230W 3.3V 256k Nonvolatile SRAM is a 262,144-bit, fully static, nonvolatile SRAM organized as 32,768 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. DIP-package DS1230W devices can be used in place of existing 32k x 8 static RAMs...