Renesas 7140SA25JI

Overview

7140SA25JI from IDT is a 1K × 8 dual-port static RAM configured as a SLAVE device in MASTER/SLAVE memory expansion systems, supporting fully asynchronous left/right port access with 25 ns max read cycle time, TTL-compatible 5V ±10% operation, and industrial temperature range (–40°C to +85°C). It enables error-free 16-bit-or-wider memory systems without external arbitration logic.

For engineers reviewing the 7140SA25JI datasheet, 7140SA25JI pinout, 7140SA25JI application, or 7140SA25JI equivalent, this page delivers verified timing parameters, BUSY-input arbitration behavior, industrial-grade DC/AC specs, and real-world use cases in real-time control and dual-processor interconnects.

Technical Context

The 7140SA25JI operates as a SLAVE dual-port SRAM with dedicated BUSY input pins (BUSYL, BUSYR) that inhibit writes when asserted low - unlike the MASTER IDT7130 which drives BUSY outputs. Its port arbitration relies entirely on external BUSY signaling from a paired MASTER device.

It supports independent R/WL/R/WR-controlled read/write cycles per port, features open-drain-compatible INTL/INTR flags for cross-port interrupt signaling, and enters low-power standby (ISB1 = 30 mA typ.) when both chip enables (CEL, CER) are high. No on-chip arbitration logic is present - all conflict resolution is externally managed via BUSY handshake.

Key Specifications

Pinout & Package

7140SA25JI is packaged in a 48-pin ceramic flatpack (FP48) with 0.75" × 0.75" body size and side-brazed leads. Pin assignments follow industry-standard dual-port SRAM layout with mirrored left/right address/data/control groups.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C131-25JC, 7140SA25JI delivers hardware-enforced arbitration without external components; compared with IDT7132SA25JI, it offers optimal cost/power trade-off for 1K memory requirements while maintaining identical timing and interoperability.

Availability

7140SA25JI is available at Aetrix Electronics and suitable for real-time motion control, dual-processor interconnect, redundant communication gateway, and legacy system memory expansion requiring stable component supply across extended production lifecycles.

Supply support for 7140SA25JI 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 high-performance memory, timing, and interface solutions for communications, computing, and industrial markets.

The IDT7140 SA/LA series was designed specifically for MASTER/SLAVE dual-port SRAM expansion in deterministic real-time systems - prioritizing bus contention avoidance, low-latency arbitration, and industrial reliability over density or ultra-low power.

FAQ

What is the role of BUSYL and BUSYR on the 7140SA25JI?

On the 7140SA25JI, BUSYL and BUSYR are dedicated input pins - not outputs. When either is driven low by an external MASTER device (e.g., IDT7130), writes to the corresponding port are internally inhibited. This hardware handshake prevents memory corruption during address contention and eliminates need for software polling or external logic.

Can the 7140SA25JI operate as a standalone dual-port RAM without a MASTER device?

Yes, the 7140SA25JI can operate standalone, but only if BUSYL and BUSYR are held high (via pull-up resistors) to disable write blocking. In this mode, it functions as a standard dual-port SRAM with independent left/right access - however, concurrent writes to the same address from both ports remain unprotected and may cause undefined data.

What is the maximum clock frequency supported by the 7140SA25JI in a synchronous interface?

The 7140SA25JI is fully asynchronous and does not require a clock. Its 25 ns max read cycle time (tRC) supports reliable operation with 40 MHz bus clocks (25 ns period), assuming proper setup/hold timing for address and control signals. No internal PLL or clock multiplier is present.

How does the 7140SA25JI differ from the IDT7130 in MASTER/SLAVE configurations?

The 7140SA25JI is strictly a SLAVE device: it accepts BUSY inputs but contains no arbitration logic. The IDT7130 is the MASTER: it generates BUSY outputs, performs on-chip arbitration, and manages priority. In a system, one IDT7130 MASTER controls multiple 7140SA25JI SLAVES to scale memory width beyond 8 bits without added complexity.

Is the 7140SA25JI pin-compatible with other IDT dual-port SRAMs in the same package?

Yes - the 7140SA25JI in FP48 package shares identical pinout with IDT7130SA25JI, IDT7140LA25JI, and IDT7132SA25JI. This allows drop-in replacement for different speed grades, power variants (SA vs LA), or memory depths (1K vs 2K) without PCB redesign - provided BUSY and interrupt usage aligns with system architecture.