Renesas IDT71256L35YI8

Overview

IDT71256L35YI8 from Integrated Device Technology is a 256K (32K × 8-bit) low-power CMOS static RAM with 35ns maximum access time, TTL-compatible I/O, and 2V battery backup data retention. It operates across –40°C to +85°C industrial temperature range, consumes ≤3µA in full standby (ISB1), and supports high-density board layouts via 28-pin 300-mil SOJ packaging. Used in legacy industrial controllers requiring nonvolatile SRAM persistence during main power loss.

For engineers reviewing the IDT71256L35YI8 datasheet, IDT71256L35YI8 pinout, IDT71256L35YI8 application, or IDT71256L35YI8 equivalent, key selection criteria include verified 35ns tAA/tACS timing at 5V ±10%, guaranteed 2V data retention current ≤500µA, SOJ-28 mechanical compatibility, and MIL-STD-883 Class B compliance for ruggedized systems.

Technical Context

This device implements a fully decoded 15-bit address space (A0–A14) driving a 262,144-bit memory array with bidirectional 8-bit data bus (I/O0–I/O7). Control logic uses three independent enables-CS (chip select), WE (write enable), and OE (output enable)-to manage read/write cycles and high-impedance tri-state output behavior.

Power management relies on dual standby modes: TTL-level standby (ISB ≤3mA) when CS > VIH, and ultra-low CMOS-level full standby (ISB1 ≤3µA) when CS > VHC and f = 0. The L-version integrates battery backup capability with VDR = 2.0V minimum and ICCDR ≤500µA over full industrial temperature range.

Key Specifications

Pinout & Package

Package: 28-pin SOJ (Small Outline J-Lead), 300-mil width, lead pitch 0.050", body size 0.400" × 0.300". Compliant with JEDEC MS-012AC.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar SRAM applications.

Compared with CY62256ELL-45ZSXI and IS61LV256AL-10TLI, IDT71256L35YI8 uniquely balances 35ns speed, 5V operation, and proven 2V battery retention-making it irreplaceable in fielded industrial systems where voltage compatibility and legacy timing margins are non-negotiable.

Availability

IDT71256L35YI8 is available at Aetrix Electronics and suitable for industrial programmable logic controllers, military communication radios, medical diagnostic equipment, and avionics data recorders requiring stable component supply across extended product lifecycles.

Supply support for IDT71256L35YI8 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Integrated Device Technology (IDT), founded in 1980 and acquired by Renesas in 2019, specializes in high-performance timing, memory, and interface ICs for communications, computing, and industrial markets.

IDT71256L35YI8 belongs to IDT's legacy high-reliability SRAM product line, designed specifically for mission-critical industrial and defense systems demanding guaranteed data retention, wide temperature operation, and long-term obsolescence support.

FAQ

What is the maximum guaranteed access time for IDT71256L35YI8?

IDT71256L35YI8 has a maximum guaranteed address access time (tAA) and chip select access time (tACS) of 35ns at VCC = 5.0V ±10% and TA = –40°C to +85°C. This value is production-tested and specified in Table 12 of the official datasheet, ensuring deterministic timing for 28MHz synchronous interfaces without derating.

Does IDT71256L35YI8 support true battery backup operation?

Yes, IDT71256L35YI8 supports true battery backup: it guarantees data retention down to VCC = 2.0V (VDR) with ICCDR ≤500µA across its full industrial temperature range. This is confirmed in Table 11 of the datasheet and enables reliable operation during main power failure in systems like PLCs and medical devices.

What package type is used for IDT71256L35YI8?

IDT71256L35YI8 is packaged in a 28-pin Small Outline J-Lead (SOJ) with 300-mil width (SO28-5), as indicated in the ordering information diagram (Figure 2946 drw 13). This package features gull-wing leads, JEDEC MS-012AC compliance, and is distinct from DIP or LCC variants of the same family.

What is the standby current consumption of IDT71256L35YI8?

IDT71256L35YI8 draws ≤3µA in full standby mode (ISB1) when CS > VHC and f = 0, as specified in Table 7 for the "L" version at industrial temperature. This ultra-low current enables multi-year data retention on standard 2V lithium batteries without supplemental regulation.

Is IDT71256L35YI8 compatible with TTL-level logic interfaces?

Yes, IDT71256L35YI8 features fully TTL-compatible inputs and outputs: VIH(min) = 2.2V, VIL(max) = 0.8V, VOL(max) = 0.4V at 8mA, and VOH(min) = 2.4V at –4mA. These values match standard TTL thresholds, allowing direct connection to legacy microcontrollers and FPGAs without level-shifting circuitry.