Renesas 7026S55JI

Overview

IDT7026S55JI from IDT (Integrated Device Technology) is a high-speed 16K × 16 true dual-port static RAM with independent left/right ports, 55 ns maximum read cycle time, TTL-compatible 5V ±10% operation, and on-chip semaphore arbitration logic. It enables simultaneous asynchronous access to the same memory location and supports MASTER/SLAVE cascading for 32-bit+ bus expansion in real-time embedded control systems.

For engineers reviewing the IDT7026S55JI datasheet, IDT7026S55JI pinout, IDT7026S55JI application, or IDT7026S55JI equivalent, key selection criteria include BUSY arbitration timing (tBDD ≤ 40 ns), dual-port power-down current (ISB3 ≤ 0.2 mA), industrial temperature range (–40°C to +85°C), and 84-pin PLCC package compatibility with legacy military-grade board layouts.

Technical Context

The IDT7026S55JI implements fully asynchronous dual-port architecture with separate address, control, and I/O buses per port - no shared clock or synchronization required. Its on-chip arbitration logic resolves contention via hardware BUSY flag generation (push-pull output) when both ports access identical addresses, with tAPS = 5 ns priority setup time ensuring deterministic resolution.

It integrates full semaphore support: eight dedicated flags addressed by A0–A2, accessed via CE = VIH / SEM = VIL, enabling inter-processor coordination without external logic. The device uses CMOS process technology and supports byte-selectable writes (UBL/LBL) and output enable (OEL/OER) per port for multiplexed bus interfacing.

Key Specifications

Pinout & Package

Package: 84-pin Plastic Leaded Chip Carrier (PLCC), body size ≈ 1.15 in × 1.15 in × 0.17 in, lead finish SnPb, RoHS-compliant green variant available.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1362BV33-55AXI and AS7C3256B-55JCIN, the IDT7026S55JI uniquely delivers integrated hardware semaphore signaling, push-pull BUSY arbitration, and true dual-port concurrency - eliminating external glue logic and guaranteeing deterministic memory sharing in safety-critical industrial and aerospace systems.

Availability

IDT7026S55JI is available at Aetrix Electronics and suitable for real-time dual-processor communication, avionics flight control systems, and industrial PLC redundancy modules requiring stable component supply across extended product lifecycles.

Supply support for IDT7026S55JI 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), now part of Renesas Electronics, designs high-performance timing, memory, and interface solutions for communications, computing, and industrial markets.

The IDT7026S55JI belongs to IDT's legacy dual-port SRAM product line, engineered specifically for deterministic, low-latency memory sharing between heterogeneous processors in mission-critical embedded systems.

FAQ

What is the operating temperature range for the IDT7026S55JI?

The IDT7026S55JI is rated for industrial temperature operation from –40°C to +85°C. This specification is validated per the datasheet's Grade table and applies to all AC/DC electrical parameters under 5.0 V ±10% supply conditions. The device does not support commercial (0°C to +70°C) or military (–55°C to +125°C) grades - the 'I' suffix explicitly denotes industrial qualification.

Does the IDT7026S55JI support true simultaneous read/write to the same memory address?

Yes, the IDT7026S55JI implements true dual-port SRAM cells that allow concurrent access to identical addresses. When contention occurs, its on-chip arbitration logic asserts BUSYL or BUSYR (depending on M/S configuration) to stall one port, ensuring data integrity. This behavior is confirmed in the Functional Description section and Truth Table I of the datasheet.

What package type is used for the IDT7026S55JI?

The IDT7026S55JI is packaged in an 84-pin Plastic Leaded Chip Carrier (PLCC), as documented in the Pin Configurations section (DSC 2939/17, page 2). The package body measures approximately 1.15 in × 1.15 in × 0.17 in and uses SnPb lead finish. It is distinct from the 84-pin PGA variant offered in other IDT7026 speed grades.

How does semaphore functionality work on the IDT7026S55JI?

The IDT7026S55JI provides eight hardware semaphore flags addressed by A0–A2. To access them, CE must be VIH and SEM must be VIL. Writes occur via I/O0; reads return the flag value across all I/O0–I/O15 lines. This enables atomic resource locking between processors without software intervention - a capability verified in Truth Table III and the Functional Description.

Is the IDT7026S55JI pin-compatible with faster or slower variants like IDT7026S25JI?

Yes, all IDT7026SxxJI variants (including IDT7026S25JI, IDT7026S35JI, and IDT7026S55JI) share identical 84-pin PLCC pinouts and DC/functional behavior - only AC timing parameters differ. This allows direct speed-grade substitution in existing PCB layouts without redesign, provided system timing margins accommodate the slower 55 ns access.