Renesas 7140LA25PF

Overview

7140LA25PF from IDT is a 1K × 8 dual-port static RAM configured as a slave device in MASTER/SLAVE memory expansion systems, supporting independent asynchronous access on left and right ports with 25 ns maximum read cycle time, TTL-compatible 5V ±10% supply, 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 7140LA25PF datasheet, 7140LA25PF pinout, 7140LA25PF application, or 7140LA25PF equivalent, key selection considerations include its BUSY input behavior (not output), battery-backed data retention at 2V, low 1 µA full-standby current, and compatibility with FP48 ceramic flatpack packaging for high-reliability embedded control and avionics interfaces.

Technical Context

The 7140LA25PF operates fully asynchronously from either port, with separate address (A0L–A9L / A0R–A9R), data (I/O0L–I/O7L / I/O0R–I/O7R), and control lines (CEL/OEL/R/WL and CER/OER/R/WR). Its BUSY pins (BUSYL/BUSYR) are dedicated inputs-unlike the IDT7130 master-which internally inhibit writes during contention.

It implements on-chip arbitration via external BUSY signaling rather than internal logic, requires pull-up resistors on open-drain INTL/INTR outputs, and supports port-to-port interrupt flagging using fixed addresses (e.g., 3FF_H to set INTR, 3FE_H to reset INTL). Data retention mode activates at V_CC = 2.0 V with typical ICCDR ≤ 100 µA.

Key Specifications

Pinout & Package

7140LA25PF uses a 48-pin ceramic flatpack (FP48) package with 0.75″ × 0.75″ body size and side-brazed leads. Pin 1 is index-marked; all V_CC and GND pins must be externally decoupled.

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 7140LA25PF uniquely delivers integrated BUSY-input arbitration and guaranteed 2V data retention in a 48-pin hermetic package - making it the only option qualified for MIL-PRF-38535 QML Class V and industrial safety-critical systems requiring hardware-enforced memory coherency.

Availability

7140LA25PF is available at Aetrix Electronics and suitable for motor control systems, avionics data buffers, industrial PLC backplanes, and medical imaging subsystems requiring stable component supply across extended product lifecycles.

Supply support for 7140LA25PF 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 timing, memory interface, and RF solutions, now part of Renesas Electronics.

The IDT7140 product line delivers slave-configured dual-port SRAMs designed specifically for MASTER/SLAVE memory expansion in fault-tolerant, real-time embedded systems where hardware arbitration and data retention are mandatory.

FAQ

What is the function of BUSYL and BUSYR on the 7140LA25PF?

BUSYL and BUSYR are dedicated input pins on the 7140LA25PF - unlike the IDT7130 master, which drives them as open-drain outputs. When asserted LOW, they internally inhibit writes to the corresponding port. External pull-up resistors are required, and assertion timing must satisfy t_WB (0 ns min) and t_WH (15 ns min) per the 25 ns speed grade. This input-only behavior defines the 7140LA25PF's role as a slave in contention-managed systems.

Does the 7140LA25PF support battery backup operation?

Yes, the 7140LA25PF supports battery backup operation with guaranteed data retention at V_CC = 2.0 V. In this mode, typical data retention current (I_CCDR) is 100 µA for industrial grade units. The device automatically enters retention mode when V_CC drops below the operating threshold, preserving all 1K × 8 memory contents without external control - a key feature distinguishing the LA variant from the SA version.

What package type is used by the 7140LA25PF?

The 7140LA25PF is packaged in a 48-pin ceramic flatpack (FP48) with dimensions approximately 0.75″ × 0.75″ × 0.11″. This hermetically sealed package meets MIL-PRF-38535 QML requirements and is rated for industrial temperature operation (–40°C to +85°C). Pin 1 is index-marked, and the package uses side-brazed leads for high-reliability solder joints in aerospace and defense applications.

How does the 7140LA25PF handle port-to-port interrupts?

The 7140LA25PF uses dedicated open-drain interrupt flags: INTL (pin 7) and INTR (pin 46). Writing to fixed addresses - e.g., A0L–A9L = 3FE_H sets INTL, A0R–A9R = 3FF_H sets INTR - triggers the respective flag. Clearing requires writing to the complementary address (3FF_H clears INTL, 3FE_H clears INTR). Both outputs require external pull-up resistors and generate asynchronous signals usable for RTOS task wake-up or DMA request initiation.

Can the 7140LA25PF be used without an IDT7130 master device?

Yes, the 7140LA25PF can operate as a standalone 1K × 8 dual-port SRAM. Its BUSY inputs default HIGH (via pull-ups), enabling normal read/write operation on both ports. However, hardware arbitration is disabled without an external BUSY source - meaning simultaneous writes to the same address will result in undefined data. For autonomous use, system-level software arbitration or external logic must manage contention, whereas in MASTER/SLAVE configuration with IDT7130, hardware arbitration is fully automatic.