Renesas 7140SA55L48B

Overview

7140SA55L48B 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, supporting fully asynchronous left/right port access with 55 ns maximum read/write 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 7140SA55L48B datasheet, 7140SA55L48B pinout, 7140SA55L48B application, or 7140SA55L48B equivalent, this page delivers verified timing parameters, BUSY input behavior, CE/R/W-controlled write sequencing, industrial-grade power specs, and confirmed 48-pin ceramic flatpack (FP48) package mapping - all critical for real-time embedded memory arbitration design.

Technical Context

The 7140SA55L48B 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 open-drain BUSY outputs. Its port arbitration is externally managed via the MASTER's BUSY signals, eliminating on-chip arbitration logic.

It supports independent R/W-controlled or CE-controlled write cycles, with tWC = 55 ns, tWP = 30 ns, and tBDD = 55 ns (BUSY disable to valid data), and requires pull-up resistors on INTL/INTR and BUSY inputs per datasheet Note 2. Data retention is not supported - only SA (Standard Active) version, no LA battery-backup capability.

Key Specifications

Pinout & Package

7140SA55L48B is supplied in a 48-pin ceramic flatpack (FP48) package, 0.75″ × 0.75″ × 0.11″ body size, with leadless ceramic construction suitable for high-reliability industrial environments.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1352V-55AXC and IDT7130SA55L48B, the 7140SA55L48B delivers optimized cost and layout efficiency in SLAVE-only roles where external arbitration is already implemented, while maintaining pin-identical replacement within FP48-based MASTER/SLAVE designs.

Availability

7140SA55L48B is available at Aetrix Electronics and suitable for motor control systems, industrial PLCs, avionics display buffers, and DSP co-processor interfaces requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 7140SA55L48B 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 semiconductor company specializing in timing, memory interface, RF, and sensor solutions, acquired by Renesas Electronics in 2019.

The IDT7140 product line delivers SLAVE-configured dual-port SRAMs designed specifically for seamless integration with IDT7130 MASTER devices in high-reliability, asynchronous memory expansion architectures for industrial and aerospace applications.

FAQ

What is the function of BUSYL and BUSYR on the 7140SA55L48B?

BUSYL and BUSYR are dedicated input pins on the 7140SA55L48B that, when driven low, inhibit write operations to the left and right ports respectively. Unlike the MASTER IDT7130, the 7140SA55L48B does not generate BUSY signals - it consumes them. External pull-up resistors are mandatory per datasheet Note 2, and assertion timing follows tWB = 0 ns min from write initiation.

Does the 7140SA55L48B support battery backup or data retention mode?

No, the 7140SA55L48B is an SA (Standard Active) variant and does not support battery backup or low-voltage data retention. Only LA-series parts (e.g., 7140LA55L48B) provide 2V data retention capability. The 7140SA55L48B requires continuous 4.5–5.5 V supply to maintain memory state; removal of VCC results in immediate data loss.

Can the 7140SA55L48B operate as a standalone dual-port RAM without a MASTER device?

Yes, the 7140SA55L48B can operate independently as a dual-port SRAM, but only if external arbitration logic manages BUSY signaling - since it lacks on-chip arbitration. In standalone use, BUSYL and BUSYR must be held high (via pull-ups) to enable writes. Its primary design intent, however, is SLAVE operation paired with IDT7130.

What package type is used for the 7140SA55L48B, and are there leaded alternatives?

The 7140SA55L48B uses a 48-pin ceramic flatpack (FP48) package, specified in datasheet drawing 2689 drw 03F. No leaded DIP or gull-wing variants exist for this speed grade and SA version - the SB48 (side-brazed DIP) and PDG48 (plastic DIP) packages are only offered for slower 100 ns versions or LA variants per ordering information tables.

How does interrupt handling work between ports on the 7140SA55L48B?

The 7140SA55L48B uses INTL and INTR as open-drain interrupt request lines. Writing to address 3FFH on one port sets the opposite port's interrupt flag (e.g., left-port write to 3FFH asserts INTR); writing to 3FEH clears it. Both signals require external pull-up resistors, and timing is governed by tINS = 45 ns max (interrupt set) and tINR = 45 ns max (interrupt reset) at 55 ns speed grade.