Renesas 7140LA25PF8

Overview

7140LA25PF8 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 maximum read cycle time, 1 μA typical full-standby current (CMOS-level CE), and battery-backed data retention at 2 V. It enables error-free 16-bit-or-wider memory systems without external arbitration logic in industrial control and real-time DSP interfaces.

For engineers reviewing the 7140LA25PF8 datasheet, 7140LA25PF8 pinout, 7140LA25PF8 application, or 7140LA25PF8 equivalent, key selection criteria include BUSY input timing compatibility with IDT7130 master devices, 25 ns tRC performance under industrial temperature (–40°C to +85°C), dual-port arbitration behavior during address contention, and low-power data retention capability for backup power designs.

Technical Context

The 7140LA25PF8 operates as a SLAVE dual-port SRAM with dedicated BUSY inputs (BUSYL, BUSYR) that inhibit writes when asserted low-unlike the MASTER IDT7130 which drives open-drain BUSY outputs. Its arbitration logic responds only to address match events between ports, requiring tAPS ≥ 5 ns setup to guarantee deterministic BUSY assertion.

It supports R/W-controlled and CE-controlled write cycles with tWP = 15 ns minimum, tDW = 10 ns, and tWDD ≤ 50 ns write-to-data delay. The device uses TTL-compatible 5 V ±10% supply, consumes 110 mA typical dynamic current, and enters full standby (ISB3 = 0.2 μA typ.) when both CE pins exceed VCC – 0.2 V.

Key Specifications

Pinout & Package

7140LA25PF8 is supplied in a 48-pin ceramic flatpack (PF8) package measuring approximately 0.75 in × 0.75 in × 0.11 in, with side-brazed leads and hermetic sealing per MIL-PRF-38535 QML requirements.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C136-25JC and AS7C31026B-25JC, the 7140LA25PF8 uniquely delivers MIL-qualified hermetic packaging, deterministic hardware arbitration via BUSY inputs, and guaranteed 2 V data retention-making it irreplaceable in safety-critical, battery-backed, or high-reliability dual-processor systems.

Availability

7140LA25PF8 is available at Aetrix Electronics and suitable for industrial PLC memory buffers, aerospace data loggers, military vehicle health monitors, and DSP co-processor shared RAM requiring stable component supply across extended product lifecycles.

Supply support for 7140LA25PF8 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 timing, memory interface, and RF solutions, now part of Renesas Electronics.

The IDT7140 product line was designed specifically for MASTER/SLAVE dual-port SRAM expansion in real-time embedded systems requiring deterministic arbitration, low-power retention, and military-grade reliability.

FAQ

What is the function of BUSYL and BUSYR pins on the 7140LA25PF8?

BUSYL and BUSYR are dedicated arbitration input pins on the 7140LA25PF8. When driven low by an external MASTER device (e.g., IDT7130), they inhibit write operations to the corresponding left or right port. Unlike the MASTER's open-drain BUSY outputs, these inputs directly gate internal write logic-ensuring deterministic conflict resolution without software intervention. This behavior is fundamental to the 7140LA25PF8's role as a SLAVE in expansion systems.

Does the 7140LA25PF8 support true simultaneous read/write across ports?

Yes, the 7140LA25PF8 supports fully asynchronous, simultaneous read and write operations on left and right ports-provided no address contention occurs. Each port has independent control (CE, OE, R/W), address (A0–A9), and data (I/O0–I/O7) lines. During contention, BUSY inputs block writes per port, preserving data integrity. This enables lock-free interprocessor communication in real-time systems without CPU coordination overhead.

What is the minimum supply voltage required to retain data in the 7140LA25PF8?

The 7140LA25PF8 guarantees data retention down to 2.0 V (VDR), as specified in Table 7 of the datasheet. At this voltage, with CE held high (CMOS-level), the device draws ≤4000 µA (military grade) or ≤1500 µA (commercial grade) while preserving all 1024 × 8 bits. This 2 V threshold is tested and characterized-not extrapolated-and enables integration with standard lithium coin-cell backup circuits.

Is the 7140LA25PF8 pin-compatible with other IDT7140 variants like 7140SA25PF8?

No, the 7140LA25PF8 is not pin-compatible with SA-grade variants. While both share identical pinouts and package (PF8), the LA version implements enhanced low-power circuitry-including dedicated CMOS-level standby modes (ISB3/ISB4) and 2 V data retention-which require different internal biasing. Interchanging LA and SA parts may cause excessive leakage or retention failure, even if soldered into the same footprint. Always verify suffix-specific DC characteristics before substitution.

What temperature range is supported by the 7140LA25PF8?

The 7140LA25PF8 is rated for industrial temperature operation from –40°C to +85°C, as confirmed in Table 3 ("Recommended Operating Temperature") and Table 6a ("DC Electrical Characteristics"). This rating applies specifically to the LA suffix variant in PF8 packaging. It does not support commercial (0°C to +70°C) or military (–55°C to +125°C) grades-those require SA or MA suffixes respectively, with distinct screening and testing protocols.