Renesas 7140LA25JI8

Overview

7140LA25JI8 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, 2V data retention capability, and industrial temperature range (–40°C to +85°C). It enables error-free 16-bit-or-wider memory systems without external logic when paired with IDT7130 master.

For engineers reviewing the 7140LA25JI8 datasheet, 7140LA25JI8 pinout, 7140LA25JI8 application, or 7140LA25JI8 equivalent, key selection considerations include BUSY input behavior, low-power standby current (1 µA typical full standby), TTL-compatible 5V ±10% supply, and flatpack package compatibility for high-reliability embedded control and avionics interfaces.

Technical Context

The 7140LA25JI8 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 from the MASTER, requiring tAPS ≥ 5 ns setup for deterministic priority resolution.

It supports battery backup via 2V data retention mode (tCDR = 0 ns, VDR = 2.0 V), achieves 1 µA typical ISB3 full-standby current under CMOS-level CE control, and maintains separate I/O, address, and control pins per port for true independent asynchronous operation-enabling concurrent read/write across ports when no address contention occurs.

Key Specifications

Pinout & Package

48-pin ceramic flatpack (FP48) with 0.75″ × 0.75″ body size and side-brazed leads; pin 1 index corner marked, all VCC and GND pins require local decoupling per datasheet layout guidelines.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C130-25JC and AS7C31026B-25JIN, the 7140LA25JI8 uniquely delivers integrated BUSY-input arbitration, 2V data retention, and QML-qualified ceramic packaging-making it irreplaceable in safety-critical, battery-backed, or high-reliability dual-port memory roles.

Availability

7140LA25JI8 is available at Aetrix Electronics and suitable for avionics data buffering, industrial motion controller memory, and military radio baseband memory requiring stable component supply across extended product lifecycles.

Supply support for 7140LA25JI8 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 LA family was designed specifically for MASTER/SLAVE dual-port SRAM expansion in real-time embedded systems demanding deterministic arbitration, low-power retention, and ruggedized packaging.

FAQ

What is the role of BUSYL and BUSYR on the 7140LA25JI8?

On the 7140LA25JI8, BUSYL and BUSYR are dedicated input pins-not outputs-that must be driven low by an external MASTER device (e.g., IDT7130) to inhibit writes to the corresponding port during address contention. Unlike the MASTER, the 7140LA25JI8 does not drive these signals; they serve solely as arbitration control inputs with no internal pull-up resistors required.

Does the 7140LA25JI8 support true simultaneous read/write operations?

Yes, the 7140LA25JI8 supports fully asynchronous independent access: one port can read while the other writes, provided no address collision occurs. When both ports access the same memory location, the BUSY input mechanism (driven by the MASTER) enforces deterministic arbitration-ensuring data integrity without external logic. This behavior is confirmed in Truth Table III and timing waveforms in the datasheet.

What is the significance of the 'LA' suffix in 7140LA25JI8?

The 'LA' suffix in 7140LA25JI8 denotes the Low-Power Active/Standby variant with battery backup capability: it guarantees 2.0 V minimum VCC for data retention and achieves 1 µA typical ISB3 full-standby current under CMOS-level chip enable. This distinguishes it from the 'SA' variant, which has higher standby current (5 µA) and no specified data retention voltage.

Can the 7140LA25JI8 operate without a MASTER device like the IDT7130?

Yes-the 7140LA25JI8 functions as a standalone 8-bit dual-port SRAM when BUSYL and BUSYR are held high (non-inhibiting), allowing unrestricted read/write on both ports. However, its integrated arbitration features-including INT flag generation and BUSY-controlled write inhibition-are only fully utilized in MASTER/SLAVE configurations with IDT7130 or equivalent.

What package type does the 7140LA25JI8 use, and why does it matter?

The 7140LA25JI8 uses a 48-pin ceramic flatpack (FP48), a hermetically sealed package with side-brazed leads. This matters because it provides superior moisture resistance, thermal stability, and mechanical robustness-meeting MIL-PRF-38535 QML requirements for aerospace, defense, and industrial applications where plastic packages would risk delamination or parameter drift over time.