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70121 - Block Diagram


2K x 9 Dual-Port RAM

The 70121 is a high-speed 2K x 9 Dual-Port Static RAM designed to be used as a stand-alone 9-bit Dual- Port RAM or as a "MASTER" Dual-Port RAM together with the 70125 "SLAVE" Dual-Port in 18-bit-or-more word width systems. Using the IDT MASTER/SLAVE Dual-Port RAM approach in 18-bit-or-wider memory system applications results in full-speed, error-free operation without the need for additional discrete logic. An automatic power-down feature, controlled by CE, permits the on-chip circuitry of each port to enter a very low standby power mode.


  • Fully asynchronous operation from either port
  • MASTER 70121 easily expands data bus width to 18 bits or more using SLAVE 70125 chip
  • On-chip port arbitration logic (70121 only)
  • BUSY output flag on Master
  • BUSY input on Slave
  • INT flag for port-to-port communication
  • Battery backup operation—2V data retention
  • TTL-compatible, signal 5V (±10%) power supply
  • Available in 52-pin PLCC
  • Industrial temperature range (–40C to +85C) is available for selected speeds
  • Green parts available, see ordering information

Product Specification

Core Voltage (V)Bus Width (bits)Density (Kb)Pkg. CodeInterfaceI/O TypeAccess Time (ns)I/O Frequency (MHz)Temp. RangeArchitectureOrganizationFunctionOutput Type
5918PL52, PLG52Async5.0 V TTL25, 35, 55-40 to 85°C, 0 to 70°CDual-Port2K x 9Master, Interrupt, Busy

Product Options

Orderable Part IDPart StatusPkg. CodePkg. TypeLead Count (#)Temp. GradePb (Lead) FreeCarrier TypeSample & Buy
70121L25JActivePL52PLCC52CNoTubeCheck Availability
70121L25J8ActivePL52PLCC52CNoReelCheck Availability
70121L25JGActivePLG52PLCC52CYesTubeCheck Availability
70121L25JG8ActivePLG52PLCC52CYesReelCheck Availability
70121L35JActivePL52PLCC52CNoTubeCheck Availability
70121L35J8ActivePL52PLCC52CNoReelCheck Availability
70121L35JIPreviewPL52PLCC52INoTubeCheck Availability
70121L35JI8PreviewPL52PLCC52INoReelCheck Availability
70121L55JActivePL52PLCC52CNoTubeCheck Availability
70121L55J8ActivePL52PLCC52CNoReelCheck Availability
70121S25JActivePL52PLCC52CNoTubeCheck Availability
70121S25J8ActivePL52PLCC52CNoReelCheck Availability
70121S35JActivePL52PLCC52CNoTubeCheck Availability
70121S35J8ActivePL52PLCC52CNoReelCheck Availability
70121S55JActivePL52PLCC52CNoTubeCheck Availability
70121S55J8ActivePL52PLCC52CNoReelCheck Availability


Technical Documentation

Title Type Format File Size Datesort icon
Datasheets & Errata
70121/5 Data Sheet Datasheet PDF 193 KB Aug 27, 2014
Apps Notes & White Papers
AN-68, Dual-Port SRAM Simplifies PC-to-TMS320 Interface Application Note PDF 92 KB May 31, 2006
AN-70, Dual-Port Interrupt Expansion Application Note PDF 56 KB May 31, 2006
AN-91, The Most Commonly Asked Questions About Async Dual-Ports Application Note PDF 87 KB May 31, 2006
show all (5)
AN-253, Introduction to Multi-Port Memories Application Note PDF 36 KB May 30, 2006
AN-09, Dual-Port SRAMs Yield Bit-Slice Designs Application Note PDF 69 KB May 30, 2006
PCN#: A-0410-02, Change IDT marking logo with new IDT gridless w Product Change Notice PDF 24 KB Nov 14, 2012
PCN# A-0607-06 MMT Thailand as Alternate Assembly Facility for PLCC, SOIC 150mil/300mil Product Change Notice PDF 223 KB Oct 6, 2006
PCN#: TB-0512-01 Reel Color Changed from Blue to Black Product Change Notice PDF 729 KB Dec 16, 2005
show all (10)
PCN#: A-0412-04 - To comply with Pb-free labels - Green Products Product Change Notice PDF 80 KB Dec 14, 2004
PCN#: A-0310-01, Green Products Product Change Notice PDF 26 KB Oct 10, 2003
PCN#: A-0309-04, new mold compound G600 material Product Change Notice PDF 134 KB Oct 7, 2003
PCN # SM0308-02 Fab 2 to Fab 4 Transfer Product Change Notice PDF 124 KB Aug 15, 2003
PCN# G-0203-05 Mold Compound Product Change Notice PDF 40 KB Apr 16, 2002
PCN# G0106-01, Moisture Sensitive Label Change Product Change Notice PDF 274 KB Jun 11, 2001
PCN# G9911-05, To qualify low alpha mold compound. Product Change Notice PDF 44 KB Nov 18, 1999