Renesas 7142SA20J

Overview

7142SA20J from IDT is a 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 20 ns maximum read cycle time (tRC), 5 V ±10% supply, and industrial temperature range (–40°C to +85°C). It serves as the data-width-expansion companion to the IDT7132SA master in 16-bit-or-wider memory subsystems for real-time digital signal processors and military avionics.

For engineers reviewing the 7142SA20J datasheet, 7142SA20J pinout, 7142SA20J application, or 7142SA20J equivalent, key selection criteria include BUSY input behavior, 20 ns access timing, TTL-compatible I/O, 48-pin flatpack packaging, and compatibility with IDT7132SA-based arbitration logic - all critical for deterministic dual-port memory coherency in high-speed embedded control.

Technical Context

The 7142SA20J implements a fully independent dual-port architecture with separate address, control, and bidirectional I/O buses per port, enabling concurrent access without internal arbitration circuitry - unlike its master counterpart IDT7132SA. Its BUSY pin functions strictly as an input to gate write operations during address contention, relying entirely on external master-generated BUSY signals.

It supports two distinct power-down modes: ISB1 (both ports disabled, TTL-level inputs) and ISB3 (full CMOS-level standby), achieving 1.0 mA typical dynamic current and 0.2 mA typical full-standby current at 5 V. The device uses standard CMOS process technology and requires no external clock or refresh circuitry.

Key Specifications

Pinout & Package

7142SA20J is supplied in a 48-pin flatpack (FP48) package with 0.050-inch lead pitch, body dimensions approximately 0.75 in × 0.75 in × 0.11 in, and gold-plated leads compliant with MIL-STD-883.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C133-25JC, 7142SA20J eliminates external arbitration components and reduces board area; compared with IDT7132SA20J, it offloads arbitration responsibility to the master, enabling scalable multi-slave configurations without timing degradation.

Availability

7142SA20J is available at Aetrix Electronics and suitable for industrial motor control, military avionics, and real-time test equipment requiring stable component supply, long-term obsolescence management, and MIL-spec traceability.

Supply support for 7142SA20J 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 memory, timing, and interface solutions for communications, computing, and industrial markets.

The IDT7132/7142 product line was designed specifically for deterministic dual-port memory expansion in real-time embedded systems, emphasizing hardware-based arbitration, low-latency access, and ruggedized packaging for mission-critical environments.

FAQ

What is the function of the BUSY pins on the 7142SA20J?

The BUSYL and BUSYR pins on the 7142SA20J are dedicated inputs that accept active-low BUSY signals from an IDT7132SA master device. When asserted low, they internally inhibit write operations on the corresponding port to prevent data corruption during simultaneous address access - the 7142SA20J contains no arbitration logic and relies entirely on external BUSY control.

Can the 7142SA20J operate as a standalone dual-port RAM without a master device?

Yes, the 7142SA20J can operate as a standalone dual-port RAM, but only in non-contention scenarios where software or system-level coordination ensures no simultaneous access to identical addresses. Unlike the IDT7132SA, it lacks on-chip arbitration and BUSY generation - so hardware-enforced coherency requires pairing with a master or external logic.

What is the maximum operating frequency supported by the 7142SA20J?

The 7142SA20J supports a maximum read cycle time (tRC) of 20 ns, corresponding to a theoretical maximum sustained access rate of 50 MHz per port. This assumes proper setup/hold timing for address and control signals, and does not imply a clocked interface - the device is asynchronous with no internal clock requirement.

Which packages are available for the 7142SA20J, and is the FP48 pinout identical across speed grades?

The 7142SA20J is specified in the 48-pin flatpack (FP48) package only, as indicated by the "J" suffix in the part number. All 7142SA variants - including 20 ns, 25 ns, and 35 ns versions - share identical FP48 pinout, electrical interface, and functional behavior; only timing parameters and temperature grading differ.

Does the 7142SA20J support battery backup data retention like some LA-series variants?

No, the 7142SA20J is an SA-series device and does not support battery backup data retention. Only LA-series parts (e.g., 7142LA20J) provide 2 V data retention capability. The SA variant operates exclusively from a 5 V ±10% supply and enters low-power standby (ISB3) but retains no data below VCC minimum.