Renesas 70V26S25J8

Overview

70V26S25J8 from Integrated Device Technology is a high-speed 3.3V 16K × 16 true dual-port static RAM with independent left/right ports, 25 ns max access time (commercial/industrial), 300 mW typical active power, and on-chip semaphore logic for inter-processor resource arbitration in real-time embedded control systems.

For engineers reviewing the 70V26S25J8 datasheet, 70V26S25J8 pinout, 70V26S25J8 application, or 70V26S25J8 equivalent, key selection criteria include simultaneous asynchronous port access, BUSY flag arbitration timing (tBAA ≤ 25 ns), byte-selectable I/O (UBL/LBL), Master/Slave cascading support via M/S pin, and 84-pin PLCC packaging for legacy industrial PCB layouts.

Technical Context

The 70V26S25J8 implements fully asynchronous dual-port operation with separate address, control, and bidirectional I/O buses per port-enabling concurrent read/write to any memory location without internal contention except at identical addresses. Its hardware semaphore logic uses eight dedicated latches (addressed by A0–A2) accessed via SEM = VIL, independent of the main 16K × 16 SRAM array.

Port arbitration relies on push-pull BUSY outputs (BUSYL/BUSYR) that assert when both ports access matching addresses; in Master mode (M/S = VIH), BUSY signals stall conflicting writes, while in Slave mode (M/S = VIL), BUSY pins become write-inhibit inputs. CE-controlled power-down reduces standby current to 3.3 mW (typ.) with no external logic required.

Key Specifications

Pinout & Package

70V26S25J8 is housed in an 84-pin PLCC package with 0.050" lead pitch and 1.15 in × 1.15 in body size. All VDD (pins 14, 25, 46, 66, 72, 82) and VSS (pins 15, 26, 45, 67, 75, 83) pins require local decoupling. Pin 1 is located at corner adjacent to notch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C026V-25AXC and IDT70V27L25PF, the 70V26S25J8 uniquely combines 25 ns speed, integrated semaphores, Master/Slave configurability, and single 3.3 V supply-making it optimal for cost-sensitive, space-constrained industrial controllers needing deterministic inter-processor communication without external glue logic.

Availability

70V26S25J8 is available at Aetrix Electronics and suitable for industrial PLCs, avionics subsystems, medical imaging pipelines, and dual-core DSP platforms requiring stable component supply across extended product lifecycles.

Supply support for 70V26S25J8 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), now part of Renesas Electronics, is a fabless semiconductor company specializing in timing, memory interface, RF, and real-time interconnect solutions for communications, computing, and industrial markets.

The 70V26S25J8 belongs to IDT's high-speed 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 maximum operating temperature range for the 70V26S25J8?

The 70V26S25J8 is rated for industrial temperature operation from –40°C to +85°C. This specification is validated across all electrical parameters including access time (25 ns max), BUSY arbitration timing (tBAA ≤ 25 ns), and power consumption (300 mW active typ.). The device uses CMOS process technology optimized for thermal stability in enclosed control cabinets and unventilated enclosures common in factory automation equipment.

Does the 70V26S25J8 support true simultaneous read/write operations on both ports?

Yes, the 70V26S25J8 supports true simultaneous read/write operations on left and right ports-as long as the accessed memory addresses differ. When both ports access the same address, hardware BUSY logic asserts within 25 ns (tBAA) to stall the later-arriving write. This architecture enables full-bandwidth utilization in asymmetric workloads, such as one port streaming sensor data while the other executes control algorithms against shared state variables stored in the 70V26S25J8.

How does the semaphore function work on the 70V26S25J8?

The 70V26S25J8 includes eight dedicated semaphore latches accessible only when SEM = VIL (chip select for semaphore space). Each latch is addressed by A0–A2 and controlled via I/O0 (write) and all I/O lines (read). Writing "0" requests the token; writing "1" releases it. The 70V26S25J8 implements this entirely in hardware-no firmware overhead-enabling atomic, wait-free resource locking between processors, which is essential for hard real-time systems like motor drives and flight control.

Can the 70V26S25J8 be used in a 32-bit data bus configuration?

Yes, the 70V26S25J8 supports 32-bit expansion using its Master/Slave (M/S) pin. One device is configured as Master (M/S = VIH) to generate BUSY arbitration signals, while others operate as Slaves (M/S = VIL) accepting BUSY as write-inhibit inputs. This eliminates external logic for width expansion and maintains full 25 ns access speed across the combined 32-bit word-verified in IDT application note AN-2945 for multi-device cascading topologies.

What package type is used for the 70V26S25J8 and are there layout considerations?

The 70V26S25J8 uses an 84-pin PLCC package (1.15 in × 1.15 in, 0.050" lead pitch). Layout best practices include placing 0.1 µF ceramic capacitors directly at each VDD pin (pins 14, 25, 46, 66, 72, 82), grounding all six VSS pins (15, 26, 45, 67, 75, 83), and routing BUSYL/BUSYR with controlled impedance to avoid false arbitration triggers. The PLCC footprint is compatible with wave-solder reflow profiles used in legacy industrial PCB assembly lines.