Renesas 7143LA55J

Overview

7143LA55J from IDT is a 2K × 16-bit high-speed dual-port static RAM configured as a SLAVE device in MASTER/SLAVE memory expansion systems, with 55 ns maximum read cycle time, 1.0 mA typical full-standby current (CMOS-level inputs), and battery backup data retention at 2 V. It enables error-free 32-bit-or-wider word-width systems without external logic in industrial communications controllers.

For engineers reviewing the 7143LA55J datasheet, 7143LA55J pinout, 7143LA55J application, or 7143LA55J equivalent, this page delivers verified timing parameters, BUSY input behavior, byte-select write control, low-power LA-series operation, and validated alternatives for dual-port SRAM system design.

Technical Context

The 7143LA55J operates fully asynchronously from either port, with independent left/right address, control, and I/O buses. Its BUSY pin functions exclusively as a write-inhibit input - unlike the MASTER 7133 - enabling deterministic arbitration when paired with a 7133 device.

It supports separate upper/lower byte write enables (R/WLUB/R/WLLB and R/WRUB/R/WRLB), TTL-compatible signaling, single 5 V ±10% supply, and 2 V data retention during battery backup. No on-chip arbitration logic is present - arbitration is delegated entirely to the MASTER 7133.

Key Specifications

Pinout & Package

7143LA55J is packaged in a 68-pin PLCC (PLG68) with 0.95″ × 0.95″ footprint. Both VCC and GND pins must be connected for reliable operation; unused pins are not present - all 68 pins serve defined I/O, control, or power roles.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1362V-55AXC and IS61WV204816BLL-55NLI, the 7143LA55J uniquely delivers integrated SLAVE arbitration input behavior, guaranteed 2 V data retention, and seamless 32-bit expansion with 7133 MASTER - reducing BOM count and PCB area in industrial control designs.

Availability

7143LA55J is available at Aetrix Electronics and suitable for industrial PLC memory buffers, dual-CPU communication bridges, redundant control system caches, and traffic signal controller memory requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 7143LA55J 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), now part of Renesas Electronics, is a fabless semiconductor company specializing in timing, memory interface, and RF solutions for high-reliability systems.

The 7143LA55J belongs to IDT's legacy dual-port SRAM product line, engineered specifically for deterministic, low-latency shared-memory architectures in industrial automation and military-grade computing.

FAQ

What is the role of BUSY pins on the 7143LA55J?

The BUSY pins (BUSYL and BUSYR) on the 7143LA55J function exclusively as write-inhibit inputs - unlike the MASTER 7133, which drives BUSY as an open-drain output. When asserted HIGH, they force the corresponding port's I/Os into high-impedance and block write operations. This SLAVE-specific behavior eliminates external arbitration logic when paired with a 7133 MASTER, making the 7143LA55J essential for scalable width-expanded dual-port systems.

Does the 7143LA55J support battery backup operation?

Yes, the 7143LA55J supports battery backup data retention at 2.0 V minimum supply voltage, preserving stored memory contents during main power loss. This feature is inherent to the LA-series low-power architecture and is validated across the full industrial temperature range (−40°C to +85°C). The 7143LA55J draws only 100 µA typical retention current, enabling multi-year operation from small backup cells.

Can the 7143LA55J be used as a standalone dual-port RAM without a 7133 MASTER?

Yes, the 7143LA55J can operate as a standalone dual-port RAM with fully independent left/right port access. However, its BUSY pins must be tied HIGH (to VCC) to disable write inhibition, as they lack internal pull-ups and default to inactive logic HIGH. In standalone mode, hardware arbitration is disabled - contention resolution must be managed externally or avoided via software protocol, unlike in MASTER/SLAVE configurations.

What package options are available for the 7143LA55J?

The 7143LA55J is offered in a 68-pin PLCC (PLG68) package with 0.95″ × 0.95″ body size and 0.05″ lead pitch. This surface-mount package is RoHS-compliant and qualified for industrial reflow profiles. While the datasheet notes availability in ceramic PGA, flatpack, and 100-pin TQFP for the broader 7143 family, the 7143LA55J variant is specifically documented and stocked in PLCC only - no other packages are assigned to this speed/temperature grade.

How does the 7143LA55J differ from the 7133LA55J in system integration?

The 7143LA55J is the SLAVE device: it accepts BUSY as an input to gate writes and contains no arbitration logic. The 7133LA55J is the MASTER: it generates BUSY as an open-drain output and includes on-chip arbitration logic. In width-expanded systems, only one 7133LA55J drives BUSY signals to multiple 7143LA55J SLAVES - preventing "busy lock-out." Using two 7143LA55Js without a MASTER disables hardware arbitration entirely, requiring external management of memory contention.