Renesas 7142SA55J8

Overview

7142SA55J8 from IDT is a 2K × 8 dual-port static RAM configured as a slave device in master/slave memory expansion systems, supporting independent asynchronous read/write access on left and right ports with 55 ns maximum read cycle time, TTL-compatible 5V ±10% supply, and industrial temperature range (–40°C to +85°C). It serves as a width-expansion slave in 16-bit-or-wider memory subsystems for real-time digital signal processing.

For engineers reviewing the 7142SA55J8 datasheet, 7142SA55J8 pinout, 7142SA55J8 application, or 7142SA55J8 equivalent, key selection considerations include BUSY input functionality, 48-pin flatpack package compatibility, 55 ns timing compliance, and interoperability with IDT7132SA55J8 master devices in contention-aware dual-port architectures.

Technical Context

The 7142SA55J8 implements a fully independent dual-port architecture with separate address, control, and I/O buses per port - no shared arbitration logic on-chip. Its BUSY pin functions exclusively as an input to gate write operations during address contention, unlike the master IDT7132 which generates BUSY outputs.

It supports CE-controlled and R/W-controlled write cycles with defined tWC = 55 ns, tWP = 30 ns, and tBDD = 50 ns (BUSY disable to valid data), and operates with CMOS-level standby current ISB3 ≤ 15 µA at full CMOS input bias, enabling low-power retention modes when paired with LA-series variants.

Key Specifications

Pinout & Package

7142SA55J8 is housed in a 48-lead flatpack (FP48) package with 0.75″ × 0.75″ footprint and 0.11″ height, featuring dual-row gull-wing leads and index corner marking. All VCC and GND pins must be externally decoupled 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 CY7C136-55JC and AS7C3256B-55JC, the 7142SA55J8 delivers native hardware slave arbitration via dedicated BUSY inputs, eliminates external logic for width expansion, and maintains strict 55 ns timing across both ports - critical for deterministic real-time memory access.

Availability

7142SA55J8 is available at Aetrix Electronics and suitable for real-time digital signal processing, redundant control systems, video frame buffering, and industrial communications protocol stack buffering requiring stable component supply and long-term obsolescence management.

Supply support for 7142SA55J8 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 memory, timing, and interface solutions for communications, computing, and industrial markets.

The IDT7142 product line delivers dual-port SRAMs optimized for hardware-arbitrated, contention-aware memory expansion in deterministic embedded systems - designed specifically to pair with IDT7132 masters in width-scalable architectures.

FAQ

What is the role of BUSY pins on the 7142SA55J8?

The BUSYL and BUSYR pins on the 7142SA55J8 function strictly as inputs - not outputs - and are used to receive active-low BUSY signals from a master IDT7132 device. When asserted, they internally inhibit write operations on the corresponding port to prevent data corruption during address contention. This behavior is fixed and cannot be reconfigured, distinguishing it from master devices that generate BUSY outputs. The 7142SA55J8 relies entirely on external arbitration for conflict resolution.

Can the 7142SA55J8 operate as a standalone dual-port RAM without a master device?

Yes, the 7142SA55J8 can operate independently as a dual-port SRAM without a master IDT7132, provided BUSYL and BUSYR are held high (via pull-up resistors) to disable write inhibition. In this mode, both ports retain full read/write capability, but hardware arbitration for simultaneous accesses to the same address is disabled. Users must implement external logic or software protocols to manage contention, as the 7142SA55J8 contains no on-chip arbitration logic - unlike the IDT7132 master.

What package type is used for the 7142SA55J8 and what are its mechanical constraints?

The 7142SA55J8 is packaged in a 48-lead flatpack (FP48) with dimensions of approximately 0.75 in × 0.75 in × 0.11 in. It features a hermetically sealed ceramic body and gull-wing leads suitable for high-reliability industrial and military applications. The package requires proper thermal relief on VCC/GND pads and strict adherence to lead coplanarity specifications (< 0.006 in) during surface-mount assembly to ensure reliable solder joint formation and long-term mechanical integrity.

How does the 7142SA55J8 differ from the IDT7132SA55J8 in system integration?

The 7142SA55J8 is a slave-only device with BUSY inputs and no on-chip arbitration logic, whereas the IDT7132SA55J8 is a master with BUSY outputs and integrated port arbitration. In width-expanded systems, the 7142SA55J8 receives BUSY signals from the IDT7132SA55J8 to gate writes, enabling seamless 16-bit+ word construction without external gates. The 7142SA55J8 cannot replace the IDT7132SA55J8 in master roles, and vice versa - their pinouts and functional behaviors are deliberately asymmetric to enforce correct hierarchical usage.

What are the DC power consumption characteristics of the 7142SA55J8 at 55 ns speed grade?

At 55 ns speed grade, the 7142SA55J8 exhibits ICC ≤ 155 mA (typical) during dynamic operation with both ports active, ISB1 ≤ 65 mA (TTL-level standby), and ISB3 ≤ 15 µA (full CMOS standby) at VCC = 5.0 V and TA = +25°C. These values scale predictably across temperature: ISB3 remains ≤ 30 µA over the full –40°C to +85°C range. The SA suffix denotes standard-power operation - distinct from LA variants offering 2V data retention and sub-µA standby.