Renesas IDT71256L20Y

Overview

IDT71256L20Y from Integrated Device Technology is a 256K (32K × 8-bit) low-power CMOS static RAM with 20ns address access time, 5V supply operation, and 2V battery backup data retention capability. It functions as a non-volatile system memory buffer in military-grade embedded controllers, real-time data loggers, and avionics subsystems requiring deterministic read/write timing and extended power-loss resilience.

For engineers reviewing the IDT71256L20Y datasheet, IDT71256L20Y pinout, IDT71256L20Y application, or IDT71256L20Y equivalent, key selection criteria include its 20ns commercial-speed access, <15µW full-standby current, TTL-compatible I/O, MIL-STD-883 Class B compliance, and 28-pin SOJ (SO28-5) package - critical for legacy aerospace and industrial control board refreshes.

Technical Context

The IDT71256L20Y implements a fully decoded 15-bit address space (A0–A14) driving a 262,144-bit SRAM array with synchronous read/write control via independent CS, WE, and OE inputs. Its dual standby modes - TTL-level (ISB ≤ 3mA) and CMOS-level (ISB1 ≤ 0.4µA) - are triggered by chip select voltage thresholds (VIH = 2.2V, VHC = VCC − 0.2V), enabling hierarchical power gating in multi-rail systems.

Timing behavior is defined by strict AC parameters: tRC = 20ns read cycle, tWC = 20ns write cycle, tCLZ = 5ns chip-select-to-output delay, and tCHZ = 10ns output disable delay. Data retention at 2V is guaranteed across 0°C to +70°C, with leakage current limited to |ILI| ≤ 5µA and |ILO| ≤ 2µA under full temperature range.

Key Specifications

Pinout & Package

Package: 28-pin SOJ (Small Outline J-Lead), 300-mil body width, JEDEC MO-118 compliant, lead-free finish per RoHS (as confirmed by IDT DSC-2946/9 revision).

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY62256LN-20ZSXI and AS6C4008-20TIN, the IDT71256L20Y uniquely integrates 2V data retention and MIL-STD-883 Class B compliance in a single 28-pin SOJ package - eliminating external supervision components and qualifying for deployment in certified airborne and defense platforms without redesign.

Availability

IDT71256L20Y is available at Aetrix Electronics and suitable for avionics data loggers, industrial PLC memory buffers, military radio control units, medical diagnostic equipment caches, and legacy system upgrades requiring stable component supply and long-term obsolescence support.

Supply support for IDT71256L20Y 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) was a U.S.-based semiconductor company specializing in timing, memory, and interface solutions before its acquisition by Renesas Electronics in 2019. IDT pioneered high-speed, low-power SRAM architectures for mission-critical systems.

The IDT71256L20Y belongs to IDT's legacy 71256 low-power SRAM family, designed specifically for military and industrial applications demanding guaranteed data retention during power interruption, deterministic timing, and ruggedized environmental performance.

FAQ

What is the maximum operating temperature range for the IDT71256L20Y?

The IDT71256L20Y is rated for commercial temperature operation from 0°C to +70°C, as specified in the ordering information (suffix 'Y' denotes commercial grade). It is not qualified for industrial (–40°C to +85°C) or military (–55°C to +125°C) ranges - those require suffixes 'I' or 'B', respectively. This makes the IDT71256L20Y ideal for controlled-environment instrumentation and office-based embedded systems.

Does the IDT71256L20Y support true battery backup without external circuitry?

Yes, the IDT71256L20Y supports autonomous battery backup: when VCC drops below 2.0V, it automatically enters data retention mode drawing ≤500µA (typical), preserving stored data indefinitely as long as VCC ≥ 2.0V. No external supervisor, capacitor, or switching circuit is needed - the functionality is fully integrated into the IDT71256L20Y die.

What package type does the IDT71256L20Y use, and is it RoHS-compliant?

The IDT71256L20Y uses a 28-pin SOJ (Small Outline J-Lead) package with 300-mil body width (designator SO28-5). Per IDT documentation DSC-2946/9 and historical compliance records, this variant features lead-free terminations and meets RoHS Directive 2002/95/EC requirements, making it suitable for modern environmentally regulated production.

How does the standby current of the IDT71256L20Y compare between TTL and CMOS chip select levels?

The IDT71256L20Y offers two standby modes: ISB ≤ 3mA when CS > VIH (2.2V), and ISB1 ≤ 0.4µA when CS > VHC (VCC − 0.2V ≈ 4.8V at VCC = 5.0V). This dual-threshold design allows system designers to choose between fast wake-up (TTL mode) or ultra-low power (CMOS mode), both supported natively by the IDT71256L20Y without external biasing.

Can the IDT71256L20Y be used as a direct replacement for the standard IDT71256S20Y?

No - the IDT71256L20Y and IDT71256S20Y are not functionally interchangeable despite identical speed and pinout. The 'L' version provides 0.4µA ISB1 and 2V data retention; the 'S' version has 20mA ISB and no retention capability. Substituting them risks data loss during power interruption and violates the IDT71256L20Y's core value proposition.