Renesas 71256S100DB

Overview

71256S100DB from Renesas Electronics is a 256K (32K × 8-bit) military-grade CMOS static RAM with 100ns maximum access time, 5V ±10% supply, and -55°C to +125°C operating range. It features TTL-compatible I/O, low-power standby mode (20mA ISB), and ceramic DIP-28 (600 mil) packaging. Used in avionics data buffers and hardened embedded controllers requiring non-volatile data retention under power interruption.

For engineers reviewing the 71256S100DB datasheet, 71256S100DB pinout, 71256S100DB application, or 71256S100DB equivalent, key selection criteria include military temperature compliance (MIL-STD-883 Class B), chip-select–controlled standby current, read/write timing margins at extended temperature, and ceramic DIP package mechanical reliability in high-vibration environments.

Technical Context

This SRAM implements asynchronous parallel interface logic with independent Chip Select (CS), Output Enable (OE), and Write Enable (WE) controls. Its architecture supports two distinct standby modes: TTL-level CS-high standby (ISB = 20mA) and CMOS-level full standby (ISB1 = 20mA), both verified across the full -55°C to +125°C military temperature range.

Timing is defined by critical AC parameters including tRC = 100ns (read cycle time), tAA = 100ns (address access), tACS = 100ns (chip select access), and tWC = 100ns (write cycle time), all guaranteed for MIL-grade operation without derating. Input/Output voltage thresholds (VIH = 2.2V min, VIL = 0.8V max) ensure robust noise margin in electrically noisy platforms.

Key Specifications

Pinout & Package

71256S100DB uses a 28-pin ceramic dual in-line package (CDIP), 600 mil width, with pin 1 index marker in top-left corner when viewed from top. Pin numbering follows standard DIP convention: pins 1–14 on left side (counting down), pins 15–28 on right side (counting up).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 71256S100DB, IS61LV25616AL-10TLI offers faster access and higher density but mandates 3.3V infrastructure and lacks military qualification, while AS6C4008-10PCN matches voltage and package footprint but sacrifices hermetic sealing and extended temperature validation-making 71256S100DB irreplaceable for fielded MIL-SPEC hardware.

Availability

71256S100DB is available at Aetrix Electronics and suitable for avionics data buffering, tactical radio memory, hardened industrial PLCs, and military vehicle control units requiring stable component supply across extended lifecycle programs.

Supply support for 71256S100DB 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 Corporation is a global semiconductor leader specializing in microcontrollers, analog, power, and memory solutions for automotive, industrial, and infrastructure markets.

The 71256S series belongs to Renesas' legacy high-reliability SRAM product line, designed specifically for military and aerospace applications demanding guaranteed performance across extreme temperature, radiation, and mechanical stress conditions.

FAQ

What is the maximum operating temperature range certified for the 71256S100DB?

The 71256S100DB is fully qualified for operation from -55°C to +125°C per MIL-STD-883 Class B requirements. This rating is verified across all electrical parameters-including tRC, tAA, and ISB-without derating, making it suitable for engine-mounted or avionics bay installations where ambient extremes are routine.

Does the 71256S100DB support battery backup data retention?

No, the 71256S100DB is the standard-power variant ('S') and does not include battery backup capability. That function is exclusive to 'L'-suffix parts like 71256L100DB, which specify 2V data retention and microamp-level standby current. The 71256S100DB draws 20mA in standby and requires continuous 5V supply for data retention.

Is the 71256S100DB pin-compatible with other members of the 71256 family?

Yes, all 71256S and 71256L variants-including 71256S100DB-share identical 28-pin CDIP pinout, address/data/control signal assignments, and DC/AC electrical interface behavior. Speed grade differences (e.g., 25ns vs. 100ns) affect timing only; no PCB redesign is needed when substituting within the same package type.

What package type does the 71256S100DB use, and why is it significant?

The 71256S100DB uses a 28-pin ceramic dual in-line package (CDIP), code CD28, 600 mil width. This hermetically sealed construction prevents moisture ingress and outgassing, delivers superior thermal conductivity versus plastic packages, and maintains mechanical integrity under sustained vibration-critical for flight-critical and ground-vehicle electronics.

How does the standby power mode function on the 71256S100DB?

When CS is driven HIGH, the 71256S100DB automatically enters TTL-level standby mode (ISB = 20mA max), disabling outputs and reducing dynamic power. This occurs independently of OE or WE states and is active across the full -55°C to +125°C range, enabling predictable system-level power budgeting during idle intervals without software intervention.