Renesas 7143SA20J8

Overview

7143SA20J8 from IDT is a high-speed 2K × 16 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 max read cycle time (commercial grade), 5 V ±10% supply, and TTL-compatible I/O. It enables 32-bit-or-wider memory bus expansion without external arbitration logic in real-time industrial control and military avionics interfaces.

For engineers reviewing the 7143SA20J8 datasheet, 7143SA20J8 pinout, 7143SA20J8 application, or 7143SA20J8 equivalent, this page delivers verified timing parameters, BUSY input behavior, byte-select write control, 68-pin PLCC package mapping, and direct alternatives for dual-port SRAM system design and replacement.

Technical Context

The 7143SA20J8 operates as a SLAVE in MASTER/SLAVE dual-port configurations - its BUSY pin functions exclusively as a write-inhibit input (not output), unlike the IDT7133 MASTER which drives BUSY as an open-drain flag. It supports fully asynchronous port operation with separate CE, R/W, and OE controls per port and independent upper/lower byte write enable (R/WLUB/R/WLLB, R/WRUB/R/WRLB).

It implements hardware contention resolution via BUSY input synchronization with the MASTER (IDT7133), requiring tWH ≥ 20 ns write hold after BUSY assertion and tWB = 0 ns BUSY-to-write delay. The device uses CMOS process, supports battery backup data retention at 2 V (LA variant only), and is not equipped with on-chip arbitration logic - that resides solely in the MASTER.

Key Specifications

Pinout & Package

7143SA20J8 is packaged in a 68-pin Plastic Leaded Chip Carrier (PLCC), body size ≈ 0.95 in × 0.95 in × 0.17 in. Both VCC and GND pins must be connected for reliable operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT7143SA25J8 and CY7C136-25JC, the 7143SA20J8 delivers the fastest commercially rated access (20 ns), native SLAVE BUSY input support eliminating external arbitration components, and guaranteed compatibility in MASTER/SLAVE width-expansion topologies - making it optimal for latency-critical embedded systems.

Availability

7143SA20J8 is available at Aetrix Electronics and suitable for real-time motion control, digital signal processor interfacing, military avionics data bus, and industrial PLC memory expansion requiring stable component supply, long-term obsolescence planning, and traceable sourcing.

Supply support for 7143SA20J8 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 semiconductor company specializing in timing, memory interface, RF, and high-performance silicon solutions, now part of Renesas Electronics.

The IDT7143 family was designed specifically as SLAVE dual-port SRAMs to pair with IDT7133 MASTER devices, enabling scalable, contention-free memory expansion in deterministic embedded systems.

FAQ

What is the role of BUSY pins on the 7143SA20J8?

The BUSY pins (BUSYL and BUSYR) on the 7143SA20J8 function exclusively as inputs - unlike the IDT7133 MASTER, which drives BUSY as an open-drain output. When asserted HIGH by the MASTER, they inhibit write operations on the corresponding port. This SLAVE-only behavior eliminates external arbitration logic and ensures deterministic resolution of simultaneous access to the same memory location. The 7143SA20J8 itself does not generate BUSY signals.

Is the 7143SA20J8 pin-compatible with the IDT7133SA20J8?

Yes, the 7143SA20J8 shares identical pinout and package (68-pin PLCC) with the IDT7133SA20J8, enabling drop-in substitution in width-expanded systems - but functional compatibility requires correct role assignment: IDT7133 must serve as MASTER (providing BUSY output and arbitration), while 7143SA20J8 operates as SLAVE (accepting BUSY input). Swapping roles will cause functional failure due to missing arbitration logic in the 7143SA20J8.

Does the 7143SA20J8 support battery backup data retention?

No, the 7143SA20J8 does not support battery backup data retention. It belongs to the SA (Standard Active Power) variant series. Only LA variants (e.g., 7143LA20J8) provide 2 V data retention capability with typical standby current of 1 µA. The SA version draws 5 mW typical standby power and requires continuous 5 V supply to retain data.

What is the maximum operating frequency implied by the 20 ns read cycle time?

The 20 ns read cycle time (tRC) of the 7143SA20J8 implies a maximum sustained read rate of 50 MHz (1 / 20 ns) per port under ideal conditions. However, actual system throughput depends on address setup/hold, CE and OE timing margins, and bus turnaround delays. For guaranteed timing compliance, designs must meet all AC specifications including tAA ≤ 20 ns, tACE ≤ 20 ns, and tAOE ≤ 12 ns as specified in the official datasheet.

Can the 7143SA20J8 be used as a standalone dual-port RAM without a MASTER device?

Yes, the 7143SA20J8 can operate as a standalone dual-port RAM - both ports support independent asynchronous reads and writes without requiring a MASTER. BUSY pins may be tied HIGH (via pull-up) to disable write inhibition, or grounded to permanently block writes on a port. However, hardware contention detection and resolution require external logic or firmware coordination, since on-chip arbitration exists only in the IDT7133 MASTER.