Renesas 71256SA15TPGI

Overview

71256SA15TPGI from Renesas Electronics is a 32K × 8 (256 Kbit) high-speed CMOS static RAM with industrial temperature range (–40°C to +85°C), 15 ns access time, TTL-compatible I/O, and single 5 V supply operation. It serves as a non-refreshing, asynchronous memory buffer in real-time control systems, legacy industrial controllers, and embedded instrumentation requiring deterministic read/write timing.

For engineers reviewing the 71256SA15TPGI datasheet, 71256SA15TPGI pinout, 71256SA15TPGI application, or 71256SA15TPGI equivalent, key selection criteria include industrial-grade reliability, 28-pin PDIP package compatibility, 15 ns cycle time under full temperature range, and low standby current (ISB = 40 mA max at VCC max).

Technical Context

The 71256SA15TPGI implements fully static asynchronous circuitry-no clocks or refresh required-and uses dual-control logic with independent Chip Select (CS) and Output Enable (OE) inputs to manage data direction and output gating. Its bidirectional I/O architecture supports direct TTL-level interfacing without level-shifting.

It features two distinct standby modes: ISB (TTL-level CS deassertion, 40 mA max) and ISB1 (CMOS-level CS deassertion, 15 mA max), enabling power optimization based on system bus voltage thresholds. All timing parameters-including tAA, tRC, tWC, and tOE-are guaranteed across –40°C to +85°C for the 15 ns speed grade.

Key Specifications

Pinout & Package

71256SA15TPGI is housed in a 28-pin 300-mil Plastic Dual In-line Package (PDIP), designated PTG28 per Renesas ordering nomenclature. The package supports through-hole mounting and provides standard 0.1″ row pitch for legacy board compatibility.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY62256ELL-15ZXI and AS6C4008-15ZIN, the 71256SA15TPGI uniquely retains 28-pin PDIP packaging with verified industrial temperature performance and TTL-level timing margins-making it the sole drop-in replacement for legacy 5 V systems requiring through-hole serviceability and unchanged board layouts.

Availability

71256SA15TPGI is available at Aetrix Electronics and suitable for programmable logic controllers, industrial HMIs, legacy CNC controllers, and test equipment requiring stable component supply with long-term industrial temperature qualification.

Supply support for 71256SA15TPGI 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 IoT applications.

The IDT71256SA family-now part of Renesas' legacy memory portfolio-was designed specifically for industrial and embedded systems needing reliable, pin-compatible 5 V SRAM with guaranteed timing across extended temperature ranges.

FAQ

What is the operating temperature range for the 71256SA15TPGI?

The 71256SA15TPGI is rated for industrial operation from –40°C to +85°C. This specification is guaranteed for all AC and DC parameters including tAA = 15 ns, ISB = 40 mA max, and VIH/VIL thresholds. The "I" suffix in the part number explicitly denotes industrial temperature qualification per Renesas ordering conventions.

Does the 71256SA15TPGI require a clock or refresh signal?

No, the 71256SA15TPGI uses fully static CMOS circuitry and requires no clock, refresh, or periodic access to retain data. It operates asynchronously-address and control signals directly determine read/write behavior-making it suitable for systems where deterministic timing and zero refresh overhead are critical, such as real-time PLC scan cycles.

What package type does the 71256SA15TPGI use?

The 71256SA15TPGI uses a 28-pin 300-mil Plastic Dual In-line Package (PDIP), identified by the "TPG" code in its ordering nomenclature. This through-hole package matches legacy PTG28 footprints and supports manual rework, field repair, and high-reliability industrial PCB assemblies.

How does the 71256SA15TPGI handle power management during idle periods?

The 71256SA15TPGI supports two standby modes: ISB (40 mA max) when CS is pulled above VIH (≥2.2 V), and ISB1 (15 mA max) when CS is driven above VHC (VCC – 0.2 V). This dual-threshold design allows system designers to select the appropriate low-power state based on bus voltage swing and noise margin requirements.

Is the 71256SA15TPGI pin-compatible with other 32K × 8 SRAMs in PDIP packages?

The 71256SA15TPGI follows industry-standard 28-pin PDIP pinout for 32K × 8 SRAMs (e.g., A0–A14, I/O0–I/O7, CS, OE, WE, VCC, GND). However, pin compatibility with specific alternatives like AS6C4008-15ZIN is not guaranteed due to address pin ordering differences (e.g., A13/A14 swap); always verify against functional schematics and layout footprints before substitution.