Renesas 7140SA100J8

Overview

7140SA100J8 from IDT is a 1K × 8 dual-port static RAM configured as a SLAVE device in MASTER/SLAVE memory expansion systems, supporting fully asynchronous left/right port access with 100 ns max read/write cycle time, TTL-compatible 5V ±10% supply, and industrial temperature range (–40°C to +85°C). It enables error-free 16-bit-or-wider memory systems without external arbitration logic.

For engineers reviewing the 7140SA100J8 datasheet, 7140SA100J8 pinout, 7140SA100J8 application, or 7140SA100J8 equivalent, this page delivers verified timing parameters, BUSY input behavior, CE/R/W-controlled write operation, and SLAVE-specific port arbitration constraints critical for real-time embedded memory design.

Technical Context

The 7140SA100J8 operates as a SLAVE in MASTER/SLAVE dual-port configurations, where BUSYL and BUSYR are dedicated inputs (not outputs) that inhibit writes when asserted low - unlike the MASTER IDT7130 which drives BUSY as open-drain outputs. Its arbitration logic responds only to address match events from the MASTER, requiring tAPS ≥ 5 ns setup for deterministic priority resolution.

All ports support independent asynchronous reads/writes with no internal clock; data retention is not supported (LA variant only provides 2V battery backup). The device uses CMOS technology with active power consumption of 110 mA typ. and full standby current of 1.0 mA typ. at CMOS-level CE inputs.

Key Specifications

Pinout & Package

48-pin ceramic flatpack (FP48) package with 0.75 in × 0.75 in footprint and 0.11 in height; pins arranged in dual in-line configuration with index mark at Pin 1 (GND).

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C135-100AXC and IDT7130SA100J8, the 7140SA100J8 uniquely provides SLAVE-specific BUSY input behavior and seamless integration with IDT7130, eliminating discrete arbitration components while maintaining strict 100 ns timing compliance.

Availability

7140SA100J8 is available at Aetrix Electronics and suitable for motor control systems, programmable logic controllers, digital signal processor interfaces, and avionics data acquisition requiring stable component supply across extended product lifecycles.

Supply support for 7140SA100J8 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 semiconductor company specializing in timing, memory interface, and RF solutions, now part of Renesas Electronics.

The IDT7130/7140 family was designed specifically for deterministic dual-processor intercommunication and real-time control systems requiring hardware-enforced memory arbitration without software overhead.

FAQ

What is the function of BUSYL and BUSYR pins on the 7140SA100J8?

BUSYL and BUSYR are dedicated input pins on the 7140SA100J8 - unlike the MASTER IDT7130, they do not drive signals. When asserted low, they inhibit write operations on the respective left or right port, enforcing hardware-based contention resolution in MASTER/SLAVE configurations. This behavior is intrinsic to the 7140SA100J8's SLAVE role and requires proper connection to the corresponding BUSY outputs of an IDT7130 MASTER device.

Can the 7140SA100J8 operate as a standalone dual-port RAM without a MASTER device?

Yes, the 7140SA100J8 can operate as a standalone dual-port RAM with independent left and right port access, but its BUSY inputs must be held high (via pull-up resistors) to enable writes. Without a MASTER IDT7130 driving BUSY signals, the built-in arbitration logic remains inactive, and users must implement external collision detection if concurrent writes to the same address are possible.

What is the maximum operating frequency supported by the 7140SA100J8?

While the 7140SA100J8 is a static RAM with no internal clock, its maximum effective throughput is governed by the 100 ns read/write cycle time (tRC). This corresponds to a theoretical maximum sustained access rate of 10 MHz per port under ideal conditions. Actual system-level bandwidth depends on bus protocol overhead, address setup times, and CE/OE assertion timing - all specified in the AC Electrical Characteristics tables for the 7140SA100J8.

Does the 7140SA100J8 support battery backup or data retention mode?

No, the 7140SA100J8 does not support battery backup or low-voltage data retention. That capability is exclusive to the LA variant (e.g., 7140LA100J8), which specifies 2.0 V minimum VCC for data retention. The "SA" suffix in 7140SA100J8 denotes standard active-power operation only, with no guaranteed data hold below 4.5 V.

Which package type is used by the 7140SA100J8, and what are its mechanical dimensions?

The 7140SA100J8 uses a 48-pin ceramic flatpack (FP48) package measuring approximately 0.75 inch × 0.75 inch × 0.11 inch. This hermetically sealed package provides superior moisture resistance and thermal stability compared to plastic DIP or LCC variants, making it suitable for high-reliability industrial and aerospace applications where long-term operational integrity is critical.