Renesas 7140SA25PF8

Overview

7140SA25PF8 from IDT (Integrated Device Technology) is a high-speed 1K × 8 dual-port static RAM configured as a SLAVE device in MASTER/SLAVE memory expansion systems. It supports fully asynchronous left/right port access, features BUSY input logic for contention arbitration, operates at 25ns max read cycle time (tRC), consumes 550mW typical active power, and is rated for industrial temperature range (–40°C to +85°C). It enables error-free 16-bit-or-wider memory systems without external logic.

For engineers reviewing the 7140SA25PF8 datasheet, 7140SA25PF8 pinout, 7140SA25PF8 application, or 7140SA25PF8 equivalent, this page delivers verified specifications, validated pin functions, confirmed industrial-temperature operation, exact BUSY-input timing behavior, and real-world MASTER/SLAVE system integration guidance - all specific to the 7140SA25PF8 in 48-pin flatpack (PF8) package.

Technical Context

The 7140SA25PF8 implements a true dual-port SRAM architecture with independent left (L) and right (R) address/data/control buses, enabling concurrent read/write operations from separate system buses. Its BUSY pins (BUSYL, BUSYR) are dedicated inputs - unlike the MASTER IDT7130 - used to gate write operations during port contention.

It lacks on-chip arbitration logic and INT flag generation circuitry; instead, it responds to external BUSY signals and supports interrupt flag clearing via dedicated address-match writes (e.g., A9–A0 = 3FEH for INTL reset). All control signals - CEL, CER, OEL, OER, R/WL, R/WR - are TTL-compatible with 5V ±10% supply and defined VIH/VIL thresholds.

Key Specifications

Pinout & Package

7140SA25PF8 is housed in a 48-pin ceramic flatpack (PF8), measuring approximately 0.75 in × 0.75 in × 0.11 in. All VCC pins require local decoupling; all GND pins must be solidly connected to ground plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C135-25JC, the 7140SA25PF8 reduces BOM count and layout complexity by embedding BUSY-input arbitration; compared with IDT7130SA25PF8, it provides strictly SLAVE functionality - eliminating unused arbitration logic and lowering cost in asymmetric memory expansions.

Availability

7140SA25PF8 is available at Aetrix Electronics and suitable for industrial motor control, avionics display subsystems, and automated test equipment requiring stable component supply across extended product lifecycles.

Supply support for 7140SA25PF8 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, RF, and sensor solutions, now part of Renesas Electronics.

The IDT7140SA/LA product line delivers high-reliability dual-port SRAMs optimized for real-time embedded systems requiring deterministic memory access, hardware arbitration, and industrial-temperature operation.

FAQ

What is the role of BUSYL and BUSYR on the 7140SA25PF8?

On the 7140SA25PF8, BUSYL and BUSYR are dedicated input pins - not outputs - used to inhibit writes to the left or right port respectively during memory contention. When asserted low, they block internal write operations regardless of R/WL or R/WR state, enabling hardware-coordinated access in MASTER/SLAVE configurations. This differs fundamentally from the IDT7130, where BUSY pins are open-drain outputs.

Can the 7140SA25PF8 operate as a standalone dual-port RAM without a MASTER device?

Yes, the 7140SA25PF8 can function as a standalone dual-port SRAM. Its left and right ports operate fully asynchronously with independent control signals (CEL/CER, OEL/OER, R/WL/R/WR). However, without an external BUSY source (e.g., from an IDT7130 MASTER), the BUSYL/BUSYR inputs must be held high (via pull-ups) to enable writes - effectively disabling hardware arbitration but preserving full dual-port read/write capability.

What is the maximum operating frequency supported by the 7140SA25PF8?

The 7140SA25PF8 does not specify a clock frequency; it is an asynchronous device. Its performance is defined by timing parameters: maximum read cycle time (tRC) is 25 ns, meaning it supports sustained read operations at up to 40 MHz (1/25 ns). Write cycle time (tWC) is also 25 ns, enabling matching write throughput. Actual system speed depends on board layout, signal integrity, and external driver strength.

How does interrupt handling work on the 7140SA25PF8?

The 7140SA25PF8 supports interrupt flag management via address-mapped writes: writing to address 3FFH sets the INTR flag, and writing to 3FEH clears the INTL flag. INTL is an output that reflects the left-port interrupt status; INTR is an input used to trigger clearing. No internal interrupt generation logic exists - flag state changes are purely address-triggered, requiring precise address decoding in the host system.

Is the 7140SA25PF8 pin-compatible with other IDT7140 speed grades or packages?

Yes - all IDT7140SA variants (e.g., 7140SA20, 7140SA35, 7140SA55) share identical pinouts and electrical characteristics across the 48-pin flatpack (PF8) package. Speed grade differences affect only AC timing parameters (tRC, tAA, etc.), not pin function or DC behavior. Migration between speed grades requires only timing validation, not PCB redesign.