Renesas 7142LA55J

Overview

IDT7142LA55J from Integrated Device Technology (IDT) is a high-speed 2K × 8 dual-port static RAM configured as a slave device in master/slave memory expansion architectures. It features 55 ns maximum read/write cycle time, 1 mW typical standby power, battery-backed data retention at 2 V, and operates on a single 5 V ±10% supply. It is used in real-time embedded systems requiring concurrent access to shared memory by two independent controllers - such as digital signal processors and microcontrollers in radar or avionics subsystems.

For engineers reviewing the IDT7142LA55J datasheet, IDT7142LA55J pinout, IDT7142LA55J application, or IDT7142LA55J equivalent, key selection considerations include its role as a slave-only dual-port SRAM with BUSY input (not output), 48-pin flatpack or LCC packaging, industrial temperature range (–40°C to +85°C), and compatibility with IDT7132 master devices for 16-bit+ bus width expansion.

Technical Context

The IDT7142LA55J implements fully asynchronous dual-port architecture with independent left/right address, control, and I/O buses - enabling simultaneous read/write operations without internal arbitration logic. Unlike the IDT7132 master, it lacks on-chip port arbitration and instead accepts BUSY signals (BUSYL/BUSYR) as inputs to inhibit writes during address contention.

Its low-power LA variant uses CMOS technology to achieve 1 mW typical standby current (ISB3) and supports 2 V data retention mode, where CE and all inputs are held at CMOS levels and VCC is reduced to 2.0 V. Timing parameters including tRC = 55 ns, tWP = 30 ns, and tBDD = 50 ns are specified over the full industrial temperature range.

Key Specifications

Pinout & Package

Package: 48-pin Flatpack (FP48) or 48-pin Leadless Chip Carrier (LC48); both hermetically sealed, lead-frame-based packages suitable for high-reliability industrial and military applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C136-55JC and IS61LV25616AL-10TLI, the IDT7142LA55J provides native slave-only BUSY input behavior, exact 2K × 8 organization, and FP48/LC48 packaging - making it uniquely suited for drop-in replacement in existing IDT7132/7142 master/slave systems without layout or logic changes.

Availability

IDT7142LA55J is available at Aetrix Electronics and suitable for radar signal processing, digital avionics display buffering, and industrial PLC I/O mapping requiring stable component supply across extended product lifecycles.

Supply support for IDT7142LA55J 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

Integrated Device Technology (IDT), now part of Renesas Electronics, is a fabless semiconductor company specializing in timing, memory interface, RF, and sensor solutions for communications, computing, and industrial markets.

The IDT7142LA55J belongs to IDT's legacy dual-port SRAM product line, designed specifically for deterministic, low-latency inter-processor communication in safety-critical and real-time embedded systems where hardware-enforced memory coherency is essential.

FAQ

What is the function of BUSYL and BUSYR on the IDT7142LA55J?

BUSYL and BUSYR are dedicated input pins on the IDT7142LA55J that accept active-low BUSY signals from an IDT7132 master device. When asserted, they internally inhibit write operations on the corresponding port to prevent data corruption during address contention. Unlike the IDT7132, the IDT7142LA55J does not drive BUSY signals - it only responds to them as a slave.

Does the IDT7142LA55J support true dual-port arbitration without external logic?

No. The IDT7142LA55J has no on-chip arbitration logic and relies entirely on external BUSY signaling from an IDT7132 master. Its role is strictly slave-only: it accepts BUSY inputs to gate writes but cannot resolve contention autonomously. Full arbitration requires pairing with an IDT7132 in master configuration - the IDT7142LA55J alone cannot arbitrate between two independent controllers.

Can the IDT7142LA55J operate with a 3.3 V supply?

No. The IDT7142LA55J is specified only for 5.0 V ±10% (4.5–5.5 V) operation and is TTL-compatible. Applying 3.3 V violates the absolute maximum ratings and will result in undefined behavior, including failure to retain data or respond to control signals. A level-shifting interface is required for use with 3.3 V systems.

What is the significance of the 'LA' suffix in IDT7142LA55J?

The 'LA' denotes the low-power, battery-backed variant of the IDT7142. It guarantees 2 V data retention capability and achieves 0.2 µA typical full-standby current (ISB3), distinguishing it from the 'SA' (standard power) version. The '55' indicates 55 ns maximum access time, and 'J' specifies the 48-pin flatpack (FP48) package with industrial temperature range (–40°C to +85°C).

Is the IDT7142LA55J pin-compatible with other IDT7142 variants like IDT7142SA55J?

Yes - all IDT7142 variants (SA/LA, 20/25/35/55/100 ns) share identical 48-pin FP48/LC48 pinouts and electrical interface definitions. The only differences are timing performance, power consumption, and data retention capability. An IDT7142LA55J can physically replace an IDT7142SA55J on the same PCB, though system-level validation of standby current and retention behavior is recommended.