Renesas IDT71256SA20Y8

Overview

IDT71256SA20Y8 from Renesas Electronics is a 32K × 8-bit (262,144-bit) high-speed CMOS static RAM with 20 ns access time, industrial temperature range (–40°C to +85°C), TTL-compatible I/O, single 5V supply operation, and 28-pin 300-mil plastic SOJ (PJG28) packaging. It serves as main or cache memory in embedded controllers, instrumentation systems, and legacy industrial PLCs requiring deterministic asynchronous read/write timing.

For engineers reviewing the IDT71256SA20Y8 datasheet, IDT71256SA20Y8 pinout, IDT71256SA20Y8 application, or IDT71256SA20Y8 equivalent, key selection criteria include guaranteed 20 ns tAA/tRC timing at industrial temperature, low 40 mA ISB standby current, bidirectional TTL-compatible I/O pins, and compatibility with legacy 28-pin SRAM footprints in space-constrained control modules.

Technical Context

The IDT71256SA20Y8 implements fully static asynchronous circuitry-no clocks or refresh required-and uses dual-control enable logic with independent Chip Select (CS) and Output Enable (OE) inputs to support interleaved memory access and output tri-state management. Its address decoder drives a 262,144-bit memory array organized as 32,768 words × 8 bits.

It operates exclusively from a single 5.0 V ±10% supply, with VIH = 2.2 V min and VIL = 0.8 V max, ensuring robust noise margin in noisy industrial environments. Standby current drops to 40 mA under TTL-level CS deassertion and further to 15 mA under CMOS-level deassertion (CS > VHC), enabling power-aware system sleep modes.

Key Specifications

Pinout & Package

Package: 28-pin 300-mil plastic SOJ (PJG28), surface-mount, gull-wing lead form, 1.27 mm pitch, JEDEC MS-013 compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed asynchronous SRAM applications.

Compared with CY62128EV30LL-45ZSXI and AS6C4008-20ZIN, the IDT71256SA20Y8 uniquely delivers 20 ns timing at 5V in a 28-pin SOJ package - making it the only viable option for maintaining legacy 5V industrial control boards without layout or power rail changes.

Availability

IDT71256SA20Y8 is available at Aetrix Electronics and suitable for industrial PLC upgrades, avionics maintenance terminals, ruggedized HMI controllers, and legacy test equipment requiring stable component supply and long-term obsolescence mitigation.

Supply support for IDT71256SA20Y8 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

Renesas Electronics is a global semiconductor leader delivering microcontrollers, analog, power, and memory solutions for automotive, industrial, and infrastructure markets.

The IDT71256SA20Y8 belongs to Renesas' legacy high-speed CMOS SRAM product line, designed specifically for industrial and aerospace applications demanding reliable, no-refresh, 5V-compatible memory with guaranteed timing across extended temperature ranges.

FAQ

What is the operating temperature range certified for IDT71256SA20Y8?

IDT71256SA20Y8 is rated for industrial temperature operation from –40°C to +85°C. This specification is fully guaranteed per the Renesas datasheet Rev. Jun.29.20, including all AC parameters (tAA, tRC, tOE) and DC characteristics (ISB, VOH, VOL) across the full range. The "I" suffix in the part number explicitly denotes industrial grade, and the Y8 package code confirms SOJ packaging qualified to this range.

Does IDT71256SA20Y8 require a clock or refresh signal?

No, IDT71256SA20Y8 uses fully static asynchronous circuitry and requires no clock, refresh, or periodic access to retain data. It operates deterministically using only address, CS, WE, and OE control signals - a key advantage for safety-critical and low-power applications where timing predictability and zero maintenance overhead are essential. This behavior is inherent to its CMOS SRAM architecture and confirmed in the Functional Block Diagram and Description sections of the datasheet.

What is the minimum write pulse width (tWP) for IDT71256SA20Y8?

The minimum write pulse width (tWP) for IDT71256SA20Y8 is 15 ns, as specified in the AC Electrical Characteristics table for the 20 ns speed grade. This value is guaranteed over the full industrial temperature range and applies when OE is held HIGH during write cycles. If OE is asserted LOW during write, tWP must be extended to satisfy tWHZ + tDW (≥25 ns), per the Write Cycle No. 1 timing diagram notes.

Is IDT71256SA20Y8 pin-compatible with other 28-pin SRAMs like the HM62256?

IDT71256SA20Y8 shares the same 28-pin SOJ (PJG28) pinout and functional assignment (A0–A14, I/O0–I/O7, CS, WE, OE, VCC, GND) as industry-standard 32K × 8 SRAMs including the HM62256 family. However, timing parameters differ: HM62256 typically specifies 70–100 ns access, while IDT71256SA20Y8 guarantees 20 ns. Electrical compatibility is maintained due to identical TTL I/O levels and 5V supply, enabling direct socket replacement where timing margins allow.

What does the "Y8" suffix indicate in IDT71256SA20Y8?

The "Y8" suffix in IDT71256SA20Y8 indicates a 28-pin 300-mil plastic SOJ (PJG28) package supplied in tape-and-reel format (the "8"). The "Y" maps to PJG28 per Renesas' Ordering Information table, and the "8" denotes tape-and-reel packaging - critical for automated SMT assembly. This matches the pin configuration shown in Figure 2a of the datasheet and confirms industrial temperature qualification (I-grade) via the "20" speed grade and ordering context.