Renesas 7164S25DB

Overview

7164S25DB from Renesas Electronics is a 64K (8K × 8-bit) high-speed CMOS static RAM with 25 ns maximum address access time, TTL-compatible I/O, single 5V supply operation, and three-state outputs. It features dual chip select (CS1/CS2) for low-power standby mode activation and is designed for military-grade embedded systems requiring reliable data retention and deterministic timing in harsh environments.

For engineers reviewing the 7164S25DB datasheet, 7164S25DB pinout, 7164S25DB application, or 7164S25DB equivalent, this page delivers verified technical context, military-qualified timing specs, package-specific pin mapping, real-world use cases in avionics and defense computing, and two validated alternative parts with documented functional and thermal differences.

Technical Context

The 7164S25DB implements fully static asynchronous architecture-no clocks or refresh required-and uses dual chip select logic where CS1 LOW + CS2 HIGH enables active read/write, while CS1 HIGH or CS2 LOW forces automatic entry into low-power standby mode. Its memory array is organized as 8,192 words × 8 bits, with address decoding covering A0–A12.

It supports WE-controlled and CS-controlled write cycles, includes output enable (OE) for bus isolation, and guarantees data retention down to 2V only in L-version variants-this S-version operates strictly at 5V ±10% with no battery backup capability. All DC and AC parameters are specified across –55°C to +125°C per MIL-STD-883 Class B.

Key Specifications

Pinout & Package

7164S25DB is housed in a 28-pin 600-mil CERDIP (CD28) package-hermetic, ceramic dual in-line with 0.6-inch body width and 0.3-inch lead spacing-designed for high-reliability military applications requiring long-term stability under thermal cycling and humidity exposure.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AS6C1008-25PCN and IS61LV25616AL-10TLI, the 7164S25DB uniquely delivers military-temperature operation, hermetic CERDIP packaging, and dual-CS standby control in a pin-compatible 28-pin footprint-making it irreplaceable in legacy defense hardware sustainment without board-level redesign.

Availability

7164S25DB is available at Aetrix Electronics and suitable for avionics flight control units, tactical radio baseband processors, ground vehicle engine control modules, and artillery fire control computers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 7164S25DB 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 delivering microcontrollers, analog, power, and memory solutions for automotive, industrial, and infrastructure markets.

The 7164S25DB belongs to Renesas' legacy high-reliability SRAM product line, engineered specifically for military and aerospace applications demanding guaranteed performance across extreme temperatures and long-term operational integrity.

FAQ

What is the operating temperature range certified for the 7164S25DB?

The 7164S25DB is fully qualified for operation from –55°C to +125°C per MIL-STD-883 Class B requirements. This specification is verified through temperature cycling, burn-in, and parametric testing at extremes-not just rated or characterized. The 7164S25DB maintains its 25 ns maximum access time and full functionality across this entire range, making it suitable for deployment in jet engine bays, missile guidance sections, and desert-deployed command posts.

Does the 7164S25DB support battery backup or low-voltage data retention?

No-the 7164S25DB is the standard-power variant and does not support battery backup or sub-5V data retention. Only the 'L' suffix versions (e.g., 7164L25DB) guarantee data retention down to 2.0 V. The 7164S25DB requires continuous 5.0 V ±10% supply for both active and standby operation; applying voltages below 4.5 V may result in data loss or undefined behavior.

What package type is used for the 7164S25DB, and why is it significant?

The 7164S25DB uses a 28-pin 600-mil CERDIP (CD28) package-ceramic dual in-line with hermetic sealing. This construction provides superior moisture resistance, thermal conductivity, and mechanical robustness compared to plastic DIP or SOJ packages. It is critical for long-term reliability in high-humidity, high-vibration, and radiation-exposed military platforms where plastic encapsulants could outgas or delaminate.

How does the dual chip select (CS1/CS2) logic function on the 7164S25DB?

On the 7164S25DB, the device is selected only when CS1 is LOW and CS2 is HIGH. If CS1 goes HIGH or CS2 goes LOW, the device automatically enters low-power standby mode (<2 mA ICCSB). This dual-control scheme allows hierarchical power management-for example, a system controller can disable multiple SRAMs simultaneously by toggling one shared CS2 line while keeping CS1 active for selective wake-up.

Is the 7164S25DB pin-compatible with other members of the IDT7164 family?

Yes-the 7164S25DB shares identical pinout, signal definitions, and DC/AC electrical behavior with all other 28-pin variants in the IDT7164 family (e.g., 7164S20DB, 7164L25DB, 7164S35DB), regardless of speed grade or temperature grade. This allows direct substitution within the same package footprint, provided the application's timing and thermal requirements are met by the replacement part.