Renesas 7133LA90J8

Overview

7133LA90J8 from IDT is a high-speed 2K × 16 dual-port static RAM with master arbitration logic, 90 ns maximum read cycle time, 2V data retention capability, and industrial temperature range (–40°C to +85°C). It serves as a stand-alone 16-bit memory or MASTER in 32-bit+ width-expansion systems with IDT7143 SLAVE devices, used in real-time embedded control and military-grade avionics interfaces.

For engineers reviewing the 7133LA90J8 datasheet, 7133LA90J8 pinout, 7133LA90J8 application, or 7133LA90J8 equivalent, key selection criteria include bus contention arbitration timing (tBDD ≤ 40 ns), low standby current (ISB3 = 0.2 mA typ.), battery backup support, and compatibility with TTL-level 5V ±10% supply and industrial thermal environments.

Technical Context

The 7133LA90J8 implements fully asynchronous dual-port operation with independent left/right address, control, and I/O buses. Its on-chip arbitration logic resolves simultaneous access to identical addresses by asserting BUSYL/BUSYR open-drain flags - only the IDT7133 variant includes this logic; IDT7143 uses BUSY as input-only.

It supports byte-selectable writes via separate R/WLUB/R/WLLB and R/WRUB/R/WRLB controls per port, enables power-down via CE-driven standby modes (ISB3 = 0.2 mA typ.), and retains data at VCC = 2V with ICCDR ≤ 4000 µA (military/industrial grade).

Key Specifications

Pinout & Package

7133LA90J8 is packaged in a 68-pin PLCC (PLG68) with 0.95″ × 0.95″ footprint and 0.17″ height. Both VCC and GND pins must be connected to ensure reliable operation; unused pins are not present - all 68 pins serve defined signal roles.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1371D-100AXC and IDT7143LA90J8, the 7133LA90J8 uniquely integrates arbitration logic and operates as a self-contained MASTER - eliminating external logic while guaranteeing deterministic contention resolution in safety-critical dual-CPU systems.

Availability

7133LA90J8 is available at Aetrix Electronics and suitable for real-time avionics interfaces, military radar signal buffering, and industrial PLC I/O co-processing requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 7133LA90J8 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 high-performance silicon solutions, now part of Renesas Electronics.

The IDT7133/7143 family was designed specifically for deterministic dual-processor communication in aerospace, defense, and industrial control systems - prioritizing arbitration integrity, data retention, and wide-temperature reliability over raw density or speed.

FAQ

What is the function of the BUSY pins on the 7133LA90J8?

The BUSYL and BUSYR pins on the 7133LA90J8 are open-drain outputs that signal port contention when both left and right ports attempt access to the same memory address simultaneously. As a MASTER device, the 7133LA90J8 asserts these flags to stall the contending port; external pull-up resistors are mandatory. This behavior is intrinsic to the 7133LA90J8 and differs from the SLAVE-only IDT7143, where BUSY is an input.

Does the 7133LA90J8 support true simultaneous read/write operations?

Yes - the 7133LA90J8 supports fully asynchronous, independent read and write operations on left and right ports, including simultaneous access to different addresses. When accessing the same address, its on-chip arbitration logic uses BUSY flags to enforce deterministic priority, ensuring one port proceeds while the other is stalled. This eliminates race conditions without software intervention.

What is the significance of the 'LA' suffix in 7133LA90J8?

The 'LA' in 7133LA90J8 denotes the Low-Power Active/Standby variant: it consumes 1050 mW typical active power and just 1 mW typical standby current (ISB1), versus 1150 mW/5 mW for the SA version. Crucially, LA devices also support 2V data retention - enabling battery backup operation - a feature not available in SA variants.

Can the 7133LA90J8 be used without external pull-up resistors on BUSY pins?

No - the BUSYL and BUSYR pins on the 7133LA90J8 are open-drain outputs and require external pull-up resistors to VCC to generate valid HIGH logic levels. Omitting pull-ups results in undefined or floating BUSY states, causing unreliable arbitration and potential system deadlock during contention. Typical values range from 4.7 kΩ to 10 kΩ.

How does the 7133LA90J8 handle width expansion to 32-bit or wider data paths?

The 7133LA90J8 functions as the MASTER in width-expansion configurations: one 7133LA90J8 controls arbitration and outputs BUSY signals, while one or more IDT7143LA90J8 SLAVE devices use those BUSY signals as write-inhibit inputs. This MASTER/SLAVE architecture avoids "Busy Lock-Out" by centralizing arbitration - no additional discrete logic or timing compensation is required.