Renesas 7133LA70J8

Overview

7133LA70J8 from Integrated Device Technology (IDT) is a high-speed 2K × 16 dual-port static RAM configured as a MASTER device with on-chip arbitration logic, 70 ns maximum read cycle time, 2V data retention capability, and TTL-compatible 5V ±10% single-supply operation - used in real-time embedded systems requiring concurrent CPU/DSP access to shared memory buffers.

For engineers reviewing the 7133LA70J8 datasheet, 7133LA70J8 pinout, 7133LA70J8 application, or 7133LA70J8 equivalent, key selection criteria include BUSY arbitration timing (tBDD ≤ 40 ns), low standby current (ISB3 = 0.2 mA typ.), byte-selectable write control per port, and compatibility with 68-pin PLCC packaging for legacy industrial controller designs.

Technical Context

The 7133LA70J8 implements fully asynchronous dual-port architecture with independent left/right address, control, and I/O buses - enabling simultaneous read/write operations without internal synchronization clocks. Its on-chip arbitration logic resolves port contention via open-drain BUSYL/BUSYR outputs requiring external pull-up resistors.

As a low-power LA variant, it supports battery backup operation at VCC = 2V with data retention current ≤4000 µA (military/industrial grade), while maintaining full-speed operation at 5V. The device uses CMOS high-performance fabrication and features separate upper/lower byte write enables (R/WLUB/R/WLLB and R/WRUB/R/WRLB) for granular memory management.

Key Specifications

Pinout & Package

68-pin Plastic Leaded Chip Carrier (PLCC, package code PLG68) with 0.95″ × 0.95″ footprint and 0.17″ height. Dual-row gull-wing leads; pin 1 marked by corner notch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT7143LA70J8 and CY7C133-70JC, the 7133LA70J8 uniquely provides integrated arbitration logic and MASTER functionality - eliminating external glue logic and reducing BOM count in safety-critical real-time systems requiring guaranteed contention resolution.

Availability

7133LA70J8 is available at Aetrix Electronics and suitable for industrial PLCs, avionics data loggers, and medical imaging systems requiring stable component supply with long-term lifecycle support.

Supply support for 7133LA70J8 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

Integrated Device Technology (IDT) is a fabless semiconductor company specializing in timing, memory interface, and RF solutions for communications and computing infrastructure.

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

FAQ

What is the function of the BUSY pins on the 7133LA70J8?

The BUSYL and BUSYR pins on the 7133LA70J8 are open-drain outputs that signal port contention when both ports attempt simultaneous access to the same memory location. As a MASTER device, the 7133LA70J8 asserts BUSY to stall the losing port's write operation. External pull-up resistors are required for proper logic-level operation. This hardware arbitration eliminates race conditions without software intervention - a core feature distinguishing the 7133LA70J8 from SLAVE-only variants like the 7143LA70J8.

Can the 7133LA70J8 operate with a 2V backup supply while the main 5V supply is off?

Yes, the 7133LA70J8 supports true 2V data retention mode: when VCC drops to ≥2.0V and chip enables are deasserted (CEL/CER = VIH), the device maintains stored data with ICCDR ≤4000 µA (military/industrial grade). This is enabled by its low-power LA process and does not require external circuitry. The 7133LA70J8 remains in retention mode until VCC rises above 2.0V and CE transitions low - making it suitable for black-box recorders and fail-safe controllers where uninterrupted memory persistence is critical.

How does the 7133LA70J8 differ from the SA version (e.g., 7133SA70J8)?

The 7133LA70J8 uses a low-power CMOS process yielding 1 mW typical standby power (vs. 5 mW for SA) and 2V data retention capability - features absent in the SA variant. Electrically, both share identical 70 ns timing, pinout, and arbitration logic. The LA version targets battery-backed or energy-constrained applications (e.g., portable test equipment), while the SA version prioritizes higher-speed margin in commercial-temperature systems. Both are drop-in replacements in 68-pin PLCC sockets, but LA-specific retention functionality requires validation of backup supply design.

Is the 7133LA70J8 pin-compatible with other packages in the 7133/7143 family?

Yes, the 7133LA70J8 shares identical pinout across all supported packages: 68-pin PLCC (PLG68), 68-pin ceramic PGA (GU68), 68-pin flatpack (FP68), and 100-pin TQFP (PNG100). Signal assignments for address, data, control, and BUSY pins are functionally identical. However, mechanical mounting, thermal characteristics, and lead finish differ - e.g., PLCC supports reflow soldering while PGA requires socketing. Migration between packages requires PCB layout changes but no logic redesign.

What are the key timing parameters governing arbitration in the 7133LA70J8?

Key arbitration timing parameters for the 7133LA70J8 include tBDD (BUSY Disable to Valid Data) ≤40 ns, tBAA/tBDA (BUSY Access/Disable from Address) ≤45 ns, and tAPS (Arbitration Priority Set-up) = 5 ns minimum. These define how quickly the device detects contention, asserts BUSY, and releases the winning port's data. All values are specified at 70 ns speed grade and industrial temperature range. Violating tAPS risks indeterminate BUSY assertion - so address setup must precede CE assertion by ≥5 ns in synchronous control schemes.