Renesas 7133LA20J

Overview

7133LA20J from IDT (Integrated Device Technology) is a high-speed 2K × 16 dual-port static RAM configured as a MASTER device with on-chip arbitration logic, 20 ns maximum read cycle time, 2V data retention capability, and TTL-compatible 5V ±10% operation - used in real-time embedded systems requiring concurrent CPU/DSP memory access without external arbitration logic.

For engineers reviewing the 7133LA20J datasheet, 7133LA20J pinout, 7133LA20J application, or 7133LA20J equivalent, this page delivers verified timing specs (tRC = 20 ns), power metrics (ISB3 = 0.2 mA typ.), BUSY arbitration behavior, byte-select write control per port, and 68-pin PLCC package mapping - all critical for deterministic dual-processor memory coherency design.

Technical Context

The 7133LA20J implements fully asynchronous dual-port architecture with independent left/right address, control, and I/O buses. Its on-chip arbitration logic resolves simultaneous accesses to identical addresses by asserting open-drain BUSYL/BUSYR outputs (requiring external pull-ups) and gating writes on the contended port.

As a MASTER device, it supports width expansion with SLAVE IDT7143LA20J devices via BUSY output-to-input cascading. It features separate upper/lower byte write enables (R/WLUB/R/WLLB and R/WRUB/R/WRLB), enabling partial-word writes without read-modify-write cycles.

Key Specifications

Pinout & Package

7133LA20J is packaged in a 68-pin Plastic Leaded Chip Carrier (PLCC), with dual-row gull-wing leads, body size ≈ 0.95″ × 0.95″ × 0.17″. 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 IDT7143LA20J and CY7C024AV-20JC, the 7133LA20J uniquely integrates arbitration logic and byte-select write control in a single 68-pin PLCC package - reducing BOM count and eliminating timing-critical external logic in real-time dual-processor systems.

Availability

7133LA20J is available at Aetrix Electronics and suitable for real-time DSP co-processing, industrial motion control, and avionics data logging requiring stable component supply across extended product lifecycles.

Supply support for 7133LA20J 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 IDT7133/7143 family was designed specifically for deterministic dual-processor memory sharing - delivering hardware arbitration, byte-select writes, and battery backup in a single chip to replace complex discrete logic implementations.

FAQ

What is the function of the BUSY pin on the 7133LA20J?

The BUSY pin on the 7133LA20J is an open-drain output that signals port contention when both left and right ports attempt simultaneous access to the same memory location. It must be externally pulled up to VCC. When asserted, it gates write operations on the contended port, ensuring deterministic arbitration without software intervention - a core feature distinguishing the 7133LA20J as a MASTER device.

Can the 7133LA20J operate with a 3.3V supply?

No, the 7133LA20J requires a 5.0 V ±10% supply (4.5 V to 5.5 V) and is TTL-compatible. It does not support 3.3 V operation. Using 3.3 V will result in undefined behavior, including failure to meet 20 ns timing specifications and potential data corruption. For 3.3 V dual-port SRAMs, consider newer families such as IDT70V25/70V26 or Cypress CY7C09449V.

How does the 7133LA20J differ from the 7143LA20J?

The 7133LA20J is the MASTER device with on-chip arbitration logic and open-drain BUSY outputs, while the 7143LA20J is the SLAVE device with BUSY inputs only and no internal arbitration. They share identical pinouts and timing, but only the 7133LA20J can operate standalone or coordinate multi-chip width expansion - the 7143LA20J must be paired with a 7133LA20J to function in BUSY-enabled systems.

What is the minimum voltage required to retain data in the 7133LA20J?

The 7133LA20J guarantees data retention down to 2.0 V (VDR = 2.0 V min), enabling use with backup batteries or hold-up capacitors during main power loss. At VCC = 2.0 V, typical data retention current is 100 µA, and the device maintains stored contents indefinitely as long as voltage remains ≥2.0 V and temperature stays within specification limits.

Does the 7133LA20J support partial-word writes without read-modify-write cycles?

Yes, the 7133LA20J supports true partial-word writes via dedicated upper and lower byte write enables (R/WLUB/R/WLLB for left port; R/WRUB/R/WRLB for right port). This allows writing only I/O0–I/O7 or I/O8–I/O15 independently - eliminating read-modify-write overhead and reducing bus traffic in mixed-width peripheral interfaces.