Renesas 7005L55J8

Overview

7005L55J8 from IDT is a high-speed 8K × 8 (64 Kbit) dual-port static RAM with true independent left/right ports, 55 ns maximum read cycle time, 2V data retention capability, and industrial temperature range (–40°C to +85°C). It supports simultaneous asynchronous access, on-chip semaphore arbitration, and master/slave cascading for 16-bit+ memory systems in real-time embedded controllers.

For engineers reviewing the 7005L55J8 datasheet, 7005L55J8 pinout, 7005L55J8 application, or 7005L55J8 equivalent, key selection criteria include dual-port contention handling via BUSY/SEM logic, low-power standby current (1 mA typ.), TTL-compatible 5 V ±10% operation, and TQFP-64 packaging for space-constrained industrial control modules.

Technical Context

The 7005L55J8 implements fully asynchronous dual-port architecture with separate address, data, and control buses per port (A0L–A12L/I/O0L–I/O7L vs. A0R–A12R/I/O0R–I/O7R), enabling concurrent reads/writes-even to the same location-via hardware arbitration. Its BUSY flag (output in master mode, input in slave mode) and semaphore logic (SEML/SEMR) resolve port conflicts without external logic.

It features two distinct operational modes: RAM access (CE = LOW, SEM = HIGH) and semaphore register access (CE = HIGH, SEM = LOW), with dedicated timing parameters (e.g., tSAA ≤ 55 ns, tSOP = 15 ns) and interrupt flag support (INTL/INTR) triggered by writes to specific addresses (e.g., 1FFE_H, 1FFF_H).

Key Specifications

Pinout & Package

64-pin TQFP package (PNG64), top view. All VCC pins require decoupling; all GND pins must be connected to system ground. Pin 1 index corner marked.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C028V-55AXC and IDT70V25L25PF, the 7005L55J8 delivers native 5 V TTL operation, 1 mA standby current, and proven industrial reliability - making it optimal for retrofitting legacy 5 V control systems without layout or voltage rail changes.

Availability

7005L55J8 is available at Aetrix Electronics and suitable for industrial motion controllers, avionics data loggers, dual-CPU communication buffers, and automated test equipment requiring stable component supply across extended product lifecycles.

Supply support for 7005L55J8 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, now part of Renesas Electronics.

The IDT7005 family was designed specifically for real-time embedded systems requiring deterministic inter-processor communication, such as industrial automation, aerospace data acquisition, and telecommunications infrastructure.

FAQ

What is the guaranteed maximum access time for the 7005L55J8?

The 7005L55J8 guarantees a maximum read cycle time (tRC) of 55 ns across its full industrial temperature range (–40°C to +85°C) and supply voltage (4.5 V to 5.5 V). This value is production-tested and specified in Table 13b of the official datasheet; it defines the shortest interval between successive read operations on either port.

Does the 7005L55J8 support battery backup operation, and what is the minimum retention voltage?

Yes, the 7005L55J8 supports battery backup operation with a minimum data retention voltage of 2.0 V (VDR), as confirmed in Table 9. In retention mode (CE > VHC, VIN outside valid logic range), it draws ≤4000 µA (military/industrial grade), preserving stored data during main power loss - critical for industrial black-box recorders.

How does the M/S pin configure master versus slave behavior in the 7005L55J8?

When M/S = HIGH, the 7005L55J8 operates as a master: BUSYL and BUSYR become push-pull outputs asserting during port contention. When M/S = LOW, it operates as a slave: BUSYL and BUSYR become inputs that inhibit writes when driven LOW by a master device - enabling hierarchical arbitration in multi-device systems.

Can the 7005L55J8 perform simultaneous reads from both ports to the same memory address?

Yes, the 7005L55J8 uses true dual-port SRAM cells that allow fully independent, simultaneous reads from both left and right ports to identical addresses without contention, corruption, or timing penalty - a core feature confirmed in the "Features" section and functional block diagram.

What are the key timing parameters for semaphore register access on the 7005L55J8?

Semaphore access requires CE = HIGH and SEM = LOW. Key parameters include tSAA (semaphore address access time ≤55 ns) and tSOP (semaphore update pulse ≥15 ns), both specified in Table 13b. These ensure reliable flag setting/clearing without interfering with concurrent RAM access on the opposite port.