Renesas 7142LA20J8

Overview

7142LA20J8 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, 5 V ±10% supply, and industrial temperature range (–40°C to +85°C). It features BUSY input for write arbitration, battery-backed data retention at 2 V, and low standby current of 1 µA (typ.) in full CMOS-level standby mode.

For engineers reviewing the 7142LA20J8 datasheet, 7142LA20J8 pinout, 7142LA20J8 application, or 7142LA20J8 equivalent, key selection considerations include its role as a slave in 16-bit+ width expansions, BUSY-input arbitration timing (tWB = 0 ns), 2V data retention capability, and compatibility with IDT7132 master devices in high-reliability embedded control and real-time signal buffering systems.

Technical Context

The 7142LA20J8 implements a true dual-port architecture with fully independent address, control, and I/O buses per port-no internal multiplexing or shared timing constraints. Its BUSY pin functions strictly as an input (unlike the master IDT7132's open-drain BUSY output), enabling hardware write inhibition when contention is detected by the master.

It supports two distinct power-down modes: TTL-level standby (ISB1/ISB2) and full CMOS-level standby (ISB3/ISB4), with ISB3 delivering 1 µA typical current at VCC = 5 V. The device uses standard TTL-compatible logic thresholds and requires no external clock or configuration registers-operation is purely combinatorial and level-sensitive.

Key Specifications

Pinout & Package

7142LA20J8 is packaged in a 48-pin flatpack (FP48) with 0.75 in × 0.75 in footprint and 0.11 in height, suitable for high-reliability military and industrial PCB layouts requiring hermetic sealing and thermal stability.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C133-25JC and AS7C3256B-20JIN, the 7142LA20J8 uniquely delivers 20 ns performance with integrated slave-mode BUSY arbitration and 2 V data retention - making it irreplaceable in industrial systems requiring deterministic contention resolution and battery-backed state preservation.

Availability

7142LA20J8 is available at Aetrix Electronics and suitable for real-time signal buffering, industrial motion control, avionics data logging, and automated test equipment requiring stable component supply and long-term obsolescence management.

Supply support for 7142LA20J8 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 timing, memory interface, RF, and sensor solutions, now part of Renesas Electronics since 2019.

The IDT7142 product line was designed specifically for high-reliability dual-port memory expansion in industrial, aerospace, and test equipment applications where deterministic arbitration and low-power retention are mandatory.

FAQ

What is the function of the BUSY pins on the 7142LA20J8?

The BUSYL and BUSYR pins on the 7142LA20J8 are dedicated inputs - not outputs - used exclusively in master/slave configurations. When driven low by an IDT7132 master device, they internally inhibit write operations to the corresponding port, preventing data corruption during address contention. This behavior is fixed and cannot be reconfigured, distinguishing the 7142LA20J8 from bidirectional BUSY implementations in other dual-port SRAMs.

Does the 7142LA20J8 support battery backup operation?

Yes, the 7142LA20J8 supports battery backup operation with guaranteed data retention at VCC = 2.0 V (minimum), drawing only 100 µA typical current in retention mode. This capability is exclusive to LA-series variants and is verified per Table 6 in the datasheet. The device retains full 2K × 8 memory content without refresh during main power loss, making it suitable for black-box recorders and safety-critical state storage.

Can the 7142LA20J8 operate as a standalone dual-port RAM without a master device?

Yes, the 7142LA20J8 can operate as a standalone dual-port RAM with fully independent left and right port access. However, BUSY arbitration is disabled unless externally driven - meaning simultaneous same-address writes from both ports may cause undefined data. For deterministic operation under contention, pairing with an IDT7132 master is required; standalone use is appropriate only in systems with software-managed access coordination or non-overlapping address spaces.

What package type is used for the 7142LA20J8?

The 7142LA20J8 uses a 48-pin flatpack (FP48) package with dimensions of approximately 0.75 in × 0.75 in × 0.11 in. This ceramic flatpack offers superior thermal stability, hermetic sealing, and radiation tolerance compared to plastic DIP or PLCC variants - aligning with its qualification for industrial and extended-temperature applications as specified in the ordering information.

How does the 7142LA20J8 differ from the IDT7132 series?

The 7142LA20J8 is functionally a slave device: it lacks on-chip arbitration logic and has BUSY pins configured as inputs only, whereas the IDT7132 is the master with BUSY outputs and internal priority resolution. The 7142LA20J8 also omits the IDT7132's on-chip port arbitration logic and busy flag generation circuitry - its role is strictly to respond to external BUSY signals. Both share identical memory size, speed grades, and electrical specifications, but their system roles are complementary and non-interchangeable.