Renesas 7133LA35JI8

Overview

7133LA35JI8 from IDT is a high-speed 2K × 16 dual-port static RAM configured as a MASTER device with on-chip arbitration logic, 35ns maximum read cycle time, 2V data retention capability, and industrial temperature range (–40°C to +85°C). It enables error-free 32-bit-or-wider memory expansion when paired with IDT7143 SLAVE devices in real-time embedded control systems requiring concurrent CPU and DSP access.

For engineers reviewing the 7133LA35JI8 datasheet, 7133LA35JI8 pinout, 7133LA35JI8 application, or 7133LA35JI8 equivalent, key selection criteria include BUSY arbitration timing (tBAA ≤ 35ns), low standby current (1µA typical), dual-port asynchronous operation, and 68-pin PLCC package compatibility with legacy military/industrial PCB layouts.

Technical Context

The 7133LA35JI8 implements fully independent left/right ports with separate address, control, and I/O buses, enabling true asynchronous read/write access to any memory location without internal synchronization overhead. Its MASTER-specific arbitration logic resolves port contention via open-drain BUSYL/BUSYR outputs that require external pull-up resistors.

It supports battery backup operation at VCC = 2V with 100µA typical data retention current, and features separate upper/lower byte write enables (R/WLUB/R/WLLB and R/WRUB/R/WRLB) for granular 8-bit writes per port - critical for mixed-precision data handling in digital signal processing subsystems.

Key Specifications

Pinout & Package

68-pin Plastic Leaded Chip Carrier (PLCC) package with 0.95″ × 0.95″ body size and J-lead configuration. Dual-port layout provides symmetrical left/right I/O banks, dedicated BUSY arbitration pins, and dual VCC/GND pairs for noise isolation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C024AV-35AXC and IDT7143LA35JI8, the 7133LA35JI8 uniquely integrates on-chip arbitration and operates as a self-contained MASTER - eliminating external logic while delivering deterministic 35ns latency and 1µA standby current for battery-critical industrial designs.

Availability

7133LA35JI8 is available at Aetrix Electronics and suitable for industrial motion control, avionics data hubs, telecom line card buffers, and digital signal processing interfaces requiring stable component supply across extended product lifecycles.

Supply support for 7133LA35JI8 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, and RF solutions for communications, computing, and industrial markets.

The IDT7133/7143 family was designed specifically for real-time embedded systems requiring deterministic dual-processor memory sharing - emphasizing hardware arbitration, low-power retention, and MIL-PRF-38535-compliant reliability.

FAQ

What is the primary function of the BUSY pins on the 7133LA35JI8?

The BUSYL and BUSYR pins on the 7133LA35JI8 are open-drain arbitration outputs that signal port contention when both left and right ports attempt simultaneous access to the same memory address. They require external pull-up resistors and enable hardware-stalled writes - preventing data corruption without software intervention. This behavior is exclusive to the MASTER 7133 variant; the SLAVE 7143 uses BUSY as an input only.

Does the 7133LA35JI8 support true asynchronous operation between its two ports?

Yes, the 7133LA35JI8 supports fully asynchronous operation: the left and right ports have independent address, control, and data buses with no internal synchronization requirement. Reads and writes may occur concurrently on either port, and the on-chip arbitration logic resolves conflicts at the hardware level - ensuring deterministic timing without clock domain crossing constraints or external handshaking.

What is the significance of the "LA" suffix in 7133LA35JI8?

The "LA" suffix in 7133LA35JI8 denotes the Low-Power Active/Standby variant: it consumes 1050mW typical active power and just 1mW typical standby current (ISB3), compared to 1150mW/5mW for the SA version. Crucially, LA devices also support 2V data retention - enabling battery backup operation during main power loss, a key requirement for industrial and military applications where nonvolatile state preservation is critical.

Can the 7133LA35JI8 be used without external pull-up resistors on BUSY pins?

No, the BUSYL and BUSYR pins on the 7133LA35JI8 are open-drain outputs and require external pull-up resistors to function correctly. Without them, the BUSY signal cannot transition high to indicate resolution of contention, causing indefinite stall conditions on the inhibited port. Typical values range from 4.7kΩ to 10kΩ to 5V, as specified in IDT application notes for reliable rise time and noise immunity.

How does the 7133LA35JI8 differ from the IDT7143LA35JI8 in system architecture?

The 7133LA35JI8 is a MASTER device with on-chip arbitration logic and open-drain BUSY outputs, while the IDT7143LA35JI8 is a SLAVE device with BUSY inputs only and no arbitration circuitry. In width-expanded systems, only one 7133LA35JI8 controls arbitration across multiple 7143LA35JI8 chips - eliminating "busy lock-out" by centralizing decision logic. The 7133LA35JI8 can operate standalone; the 7143LA35JI8 requires a MASTER to function in arbitration mode.