Renesas 7142SA35J8

Overview

7142SA35J8 from IDT is a high-speed 2K × 8 dual-port static RAM configured as a SLAVE device in MASTER/SLAVE memory expansion systems, supporting independent asynchronous read/write access on left and right ports with 35 ns maximum read cycle time (tRC), 35 ns address access time (tAA), and TTL-compatible 5V ±10% operation - used in real-time avionics data buffers and military-grade radar signal processing subsystems.

For engineers reviewing the 7142SA35J8 datasheet, 7142SA35J8 pinout, 7142SA35J8 application, or 7142SA35J8 equivalent, key selection considerations include its BUSY input functionality (not output), absence of on-chip arbitration logic, compatibility with IDT7132SA35J8 master devices for 16-bit+ width expansion, and qualification for industrial temperature range (–40°C to +85°C) in 48-pin flatpack packaging.

Technical Context

The 7142SA35J8 implements two fully independent address/data/control interfaces (left/right ports), each with dedicated CE, OE, R/W, A0–A10, and I/O0–I/O7 signals, enabling concurrent access without software coordination. Its BUSY pin functions exclusively as an input to inhibit writes during port contention - unlike the IDT7132 master, it contains no arbitration logic or BUSY generation circuitry.

It operates in standard TTL voltage levels (VIH = 2.2 V min, VIL = 0.8 V max), supports automatic power-down via CE assertion, and delivers full-speed operation without external glue logic when paired with IDT7132 in width-expanded configurations. The device uses CMOS process technology and requires no battery backup (LA variant only supports 2V retention).

Key Specifications

Pinout & Package

7142SA35J8 is supplied in a 48-pin flatpack (FP48) package with leads arranged in a 6×8 grid, requiring all VCC and GND pins to be connected per datasheet Note 1 and 2. Pin 1 is index-marked; body dimensions are 0.75 in × 0.75 in × 0.11 in.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C024AV-35AXC and IDT7132SA35J8, the 7142SA35J8 provides optimized cost and footprint for industrial 5V dual-port buffering where strict 2K × 8 capacity and BUSY-input-only behavior are design requirements - neither alternative replicates its exact role in width-expanded SRAM arrays.

Availability

7142SA35J8 is available at Aetrix Electronics and suitable for avionics data buffering, radar signal processing, and military communications hubs requiring stable component supply across extended production lifecycles and temperature-hardened reliability.

Supply support for 7142SA35J8 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 IDT7132/7142 product line was designed specifically for deterministic, low-latency dual-port memory applications in real-time embedded systems - emphasizing hardware arbitration, 5V robustness, and seamless width expansion without external logic.

FAQ

What is the function of the BUSY pins on the 7142SA35J8?

The BUSYL and BUSYR pins on the 7142SA35J8 serve exclusively as active-low write-inhibit inputs. Unlike the IDT7132 master, this SLAVE device does not generate BUSY signals - it responds to external BUSY assertions from a connected IDT7132 to gate internal write operations during port contention. This behavior is hardwired and non-configurable.

Can the 7142SA35J8 operate as a standalone dual-port RAM without a master device?

Yes, the 7142SA35J8 can operate as a standalone dual-port RAM with full read/write capability on both ports. However, BUSY arbitration is disabled without an external master; designers must implement software-based collision avoidance or accept potential data corruption during simultaneous accesses to identical addresses - the device lacks on-chip arbitration logic.

What is the maximum clock frequency supported by the 7142SA35J8?

The 7142SA35J8 does not use a clock signal - it is an asynchronous static RAM. Its performance is defined by timing parameters including tRC = 35 ns (minimum read cycle time) and tWC = 35 ns (minimum write cycle time), supporting effective memory bandwidth up to approximately 28.6 MHz per port when continuously cycling.

Is the 7142SA35J8 pin-compatible with the IDT7132SA35J8?

No, the 7142SA35J8 and IDT7132SA35J8 share identical pinouts in the FP48 package, but their BUSY pin functionality differs fundamentally: BUSY pins are outputs on the 7132 (open-drain) and inputs on the 7142. Direct substitution without modifying external BUSY routing will cause functional failure.

Does the 7142SA35J8 support battery backup for data retention?

No, the 7142SA35J8 is the SA (standard power) variant and does not support battery backup. Only LA variants (e.g., 7142LA35J8) provide 2V data retention capability. The SA version requires continuous 5V supply to maintain memory contents and exhibits typical ISB3 standby current of 0.2 mA.