Renesas 7140SA20J8

Overview

7140SA20J8 from IDT is a high-speed 1K × 8 dual-port static RAM configured as a SLAVE device in MASTER/SLAVE memory expansion systems, supporting independent asynchronous access on left and right ports with 20 ns max read cycle time, TTL-compatible 5V ±10% supply, and industrial temperature range (–40°C to +85°C); used in real-time DSP co-processing and legacy bus arbitration systems.

For engineers reviewing the 7140SA20J8 datasheet, 7140SA20J8 pinout, 7140SA20J8 application, or 7140SA20J8 equivalent, this page delivers verified timing parameters, BUSY input behavior, port-to-port arbitration constraints, and direct replacement guidance for 16-bit-or-wider memory subsystems requiring deterministic contention resolution.

Technical Context

The 7140SA20J8 operates as a SLAVE dual-port SRAM with dedicated BUSY input pins (BUSYL, BUSYR) that inhibit writes when asserted low-unlike the MASTER IDT7130 which drives BUSY outputs. It lacks on-chip arbitration logic and relies entirely on external BUSY signaling from the MASTER for conflict resolution.

Its 20 ns speed grade defines tRC = 20 ns, tAA ≤ 20 ns, tACE ≤ 20 ns, and tAOE ≤ 11 ns under commercial conditions; all I/Os are TTL-compatible with VIL ≤ 0.8 V and VOH ≥ 2.4 V at IOH = –4 mA, and it supports full asynchronous operation with separate CE, OE, and R/W controls per port.

Key Specifications

Pinout & Package

7140SA20J8 is supplied in a 48-pin ceramic flatpack (FP48) package with 0.75″ × 0.75″ footprint and 0.11″ height, compliant with MIL-PRF-38535 QML Class V for high-reliability applications.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-port SRAM applications.

Compared with CY7C131-20JC and IDT7130SA20J8, the 7140SA20J8 delivers minimal-footprint SLAVE functionality with strict BUSY-input dependency, enabling cost-optimized memory expansion where arbitration is centralized in the MASTER device.

Availability

7140SA20J8 is available at Aetrix Electronics and suitable for real-time DSP co-processing, avionics data acquisition, and military radar front-end buffering requiring stable component supply across extended production lifecycles.

Supply support for 7140SA20J8 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

IDT (Integrated Device Technology) is a fabless semiconductor company specializing in high-performance timing, memory, and interface solutions for communications, computing, and industrial markets.

The IDT7130/7140 family was designed specifically for deterministic, low-latency dual-ported memory expansion in multi-processor systems where hardware-controlled arbitration replaces software locks.

FAQ

What is the function of BUSYL and BUSYR on the 7140SA20J8?

On the 7140SA20J8, BUSYL and BUSYR are active-low input pins that inhibit writes to the left and right ports respectively when driven low by an external MASTER device (e.g., IDT7130SA20J8). These pins do not drive outputs and require external pull-up resistors. The 7140SA20J8 contains no internal arbitration logic-BUSY behavior is entirely externally controlled.

Can the 7140SA20J8 operate as a standalone dual-port RAM without a MASTER device?

No-the 7140SA20J8 is explicitly designed as a SLAVE device and lacks on-chip arbitration logic, BUSY output capability, and INT flag generation logic found in the MASTER IDT7130. Without an external MASTER driving BUSY signals and managing contention, concurrent writes to overlapping addresses will result in undefined data. The 7140SA20J8 must be paired with IDT7130 in all functional implementations.

What package type is used for the 7140SA20J8 and what does the 'J8' suffix indicate?

The 7140SA20J8 uses a 48-pin ceramic flatpack (FP48) package, hermetically sealed and qualified to MIL-PRF-38535 QML Class V. The 'J8' suffix denotes the ceramic flatpack configuration with standard lead finish and industrial temperature range (–40°C to +85°C), distinguishing it from plastic DIP (J), LCC (L), or TQFP (P) variants.

Does the 7140SA20J8 support battery backup or data retention below 5V?

No-the 'SA' suffix indicates the standard power version, which requires a nominal 5V ±10% supply and does not support battery backup. Data retention below 4.5V is not guaranteed. For 2V data retention capability, the LA variant (e.g., 7140LA20J8) must be selected; the 7140SA20J8 has no low-voltage retention mode.

How does interrupt handling work on the 7140SA20J8?

The 7140SA20J8 provides open-drain INTL and INTR outputs that assert low when a port writes to the predefined interrupt address (e.g., A9–A0 = 3FFh for right-port interrupt set). These flags remain active until cleared by a write to the corresponding reset address (e.g., 3FEh). No internal interrupt masking or priority encoding is implemented-the host processor must poll or edge-detect these signals externally.