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72V3656 - Block Diagram


2K x 36 x 2 Triple-Bus FIFO, 3.3V

The 72V3656 is a 2K x 36 x 2 Triple Bus sync FIFO memory that is a 3.3V version of the 723656. The enables for each port are arranged to provide a simple bidirectional interface between microprocessors and/or buses with synchronous control. This device can operate in the IDT Standard mode or First Word Fall Through mode. Two 72V3656 FIFO’s can be combined with unidirectional FIFO’s capable of First Word Fall Through timing (i.e. the SuperSync FIFO family) to form a depth expansion.


  • Clock frequencies up to 100 MHz (6.5ns access time)
  • Two independent FIFOs buffer data between one bidirectional 36-bit port and two unidirectional 18-bit ports
  • Programmable Almost-Empty and Almost-Full flags
  • Serial or parallel programming of partial flags
  • Big- or Little-Endian format for word and byte bus sizes
  • Loopback mode on Port A
  • Retransmit Capability
  • Master Reset clears data and configures FIFO, Partial Reset clears data but retains configuration settings
  • Mailbox bypass registers for each FIFO
  • Auto power down minimizes power dissipation
  • Available in 128-pin TQFP package
  • Industrial temperature range (–40C to +85C) is available

Product Specification

Core Voltage (V)Bus Width (bits)Density (Kb)Pkg. CodeInterfaceI/O TypeI/O Frequency (MHz)Cycle Time (ns)OrganizationTemp. RangeArchitectureAccess Time (ns)
3.336144PK128Synchronous3.3 V LVTTL66.00, 100.002K x 36 x 2-40 to 85°C, 0 to 70°CBi-directional

Product Options

Orderable Part IDPart StatusPkg. CodePkg. TypeLead Count (#)Temp. GradePb (Lead) FreeCarrier TypeSample & Buy
72V3656L10PFActivePK128TQFP128CNoTrayCheck Availability
72V3656L10PF8ActivePK128TQFP128CNoReelCheck Availability
72V3656L10PFIActivePK128TQFP128INoTrayCheck Availability
72V3656L10PFI8ActivePK128TQFP128INoReelCheck Availability
72V3656L15PFActivePK128TQFP128CNoTrayCheck Availability
72V3656L15PF8ActivePK128TQFP128CNoReelCheck Availability


Technical Documentation

Title Type Format File Size Datesort icon
Datasheets & Errata
72V3656-72V3676 Datasheet Datasheet PDF 390 KB Feb 12, 2009
PCN#: A1309-03 Additional Assembly Sources Product Change Notice PDF 398 KB Oct 21, 2013
PCN#: A-0410-02, Change IDT marking logo with new IDT gridless w Product Change Notice PDF 24 KB Nov 14, 2012
A-0603-04 Transfer TQFP and PQFP from ASAT HK to ASAT China Product Change Notice PDF 164 KB May 10, 2006
show all (12)
PCN A-0506-03; Packing Material Change Product Change Notice PDF 290 KB Jul 19, 2005
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#G-0302-05, New mold compound EME-G700 series Product Change Notice PDF 65 KB Mar 20, 2003
PCN#: G-0302-06, New die attach 3230 from Ablestik Product Change Notice PDF 150 KB Mar 20, 2003
PCN# G-0110-06 REV.1 Mold Compound Product Change Notice PDF 48 KB Apr 26, 2002
PCN# G-0110-06 Mold Compound Product Change Notice PDF 47 KB Dec 14, 2001
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