DS3803

www.DataSheet4U.com DS3803 1024k Flexible NV SRAM SIMM www.dalsemi.com FEATURES Flexibly organized as 32k x 32, 64k x 16 or 128k x 8bits 10 years minimum data retention in the absence of external power Nonvolatile circuitry transparent to and independent from host system Automatic write protection circuitry safeguards against data loss Separate control and data signals for each SRAM allow byte, word or doubleword access Fast access time of 70 ns Full VCC ± 10% operating range Employs popular JEDEC standard 72-position SIMM connector Extremely thin design built using TSOPpackage IC components PIN ASSIGNMENT 1 256K SRAM 256K SRAM 256K SRAM 256K SRAM DS3803 72-Pin SIMM PIN DESCRIPTION A0 - A14 D0A - D7A D0B - D7B D0C - D7C D0D - D7D CEA - CED WEA - WED OEA - OED VCC GND NC Address Inputs Data Inputs/Outputs, Byte A Data Inputs/Outputs, Byte B Data Inputs/Outputs, Byte C Data Inputs/Outputs, Byte D Chip Enable Inputs Write Enable Inputs Output Enable Inputs +5V Power Supply Ground No Connect 72 DESCRIPTION The DS3803 is a self-contained, 1,048,576-bit, nonvolatile static RAM which can be flexibly organized as 32k x 32, 64k x 16 or 128k x 8. Built using four 32k x 8 SRAMs, four nonvolatile control ICs and four lithium batteries, this nonvolatile memory contains all necessary control circuitry and lithium energy sources to maintain data integrity in the absence of power for more than 10 years. The DS3803 employs the popular JEDEC standard 72-position SIMM connection scheme a...