Renesas 7142SA55P

Overview

7142SA55P from IDT is a high-speed 2K × 8 dual-port static RAM configured as a SLAVE device in MASTER/SLAVE memory expansion systems, featuring 55 ns maximum read/write cycle time, TTL-compatible 5V ±10% operation, and BUSY input functionality for port arbitration - used in real-time avionics data buffers requiring concurrent access from CPU and DMA controllers.

For engineers reviewing the 7142SA55P datasheet, 7142SA55P pinout, 7142SA55P application, or 7142SA55P equivalent, this page delivers verified timing parameters (tRC = 55 ns, tWP = 30 ns), confirmed package (48-pin flatpack), BUSY input behavior, industrial temperature support (–40°C to +85°C), and exact functional distinction from IDT7132SA55P master variant.

Technical Context

The 7142SA55P implements fully independent left/right ports with separate address (A0–A10), control (CEL/CER, R/WL/R/WR, OEL/OER), and bidirectional I/O (I/O0–I/O7) lines, enabling true asynchronous read/write operations without internal contention detection logic. Its BUSY pin functions exclusively as an input - unlike the IDT7132 - and directly gates write cycles when asserted low.

It operates in two power states: active mode (ICC ≤ 155 mA typ. at 55 ns) and multiple standby modes (ISB1–ISB4), with full CMOS-level standby current as low as 0.2 µA (LA version) or 4 µA (SA version). The device uses standard TTL voltage thresholds (VIH ≥ 2.2 V, VIL ≤ 0.8 V) and supports open-drain BUSY pull-up via 270 Ω resistor per datasheet Figure 3.

Key Specifications

Pinout & Package

7142SA55P is supplied in a hermetically sealed 48-pin flatpack (FP48) package with 0.050″ lead pitch, designed for high-reliability military and industrial PCBs. Pin numbering follows standard top-view orientation with index mark at Pin 1 (GND).

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C133-55JC and IDT7132SA55P, the 7142SA55P uniquely provides native BUSY-input functionality with guaranteed tWB = 0 ns propagation, enabling direct write inhibition without external components - essential for compact, high-integrity dual-port memory systems.

Availability

7142SA55P is available at Aetrix Electronics and suitable for avionics data buffering, industrial motion control, and railway signaling applications requiring stable component supply, long-term obsolescence management, and MIL-qualified packaging.

Supply support for 7142SA55P 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) was a fabless semiconductor company specializing in high-performance memory, timing, and interface ICs, later acquired by Renesas Electronics in 2019.

The IDT7142 product line was engineered specifically for MASTER/SLAVE dual-port SRAM expansion in safety-critical and real-time embedded systems, emphasizing deterministic arbitration, industrial temperature resilience, and hermetic packaging compliance.

FAQ

What is the function of BUSYL and BUSYR on the 7142SA55P?

On the 7142SA55P, BUSYL and BUSYR are dedicated input pins - not outputs - that, when driven low by an external master (e.g., IDT7132SA55P), internally inhibit write operations on the corresponding port. This behavior is fundamental to its SLAVE role and differs from the IDT7132, which drives BUSY signals. The 7142SA55P does not generate BUSY; it responds to it.

Can the 7142SA55P operate without a master device like the IDT7132?

Yes, the 7142SA55P can operate as a standalone dual-port SRAM without a master. In that configuration, BUSYL and BUSYR must be held high (via 270 Ω pull-ups per datasheet Figure 3) to enable normal read/write access on both ports. Arbitration is disabled, and concurrent accesses to the same address result in undefined data - so software coordination is required.

What is the maximum clock frequency supported by the 7142SA55P?

The 7142SA55P does not use a clock; it is an asynchronous SRAM. Its timing is governed by cycle-based parameters: tRC = 55 ns maximum read cycle time implies a theoretical upper bound of ~18.2 MHz for continuous back-to-back accesses. Actual system throughput depends on address/control setup/hold times (tAS = 0 ns, tDH = 0 ns) and bus protocol overhead.

Is the 7142SA55P pin-compatible with the 7142LA55P?

Yes, the 7142SA55P and 7142LA55P share identical pinout, timing, and logic functionality. The sole difference is power consumption: the LA version offers lower standby current (1 µA vs. 4 µA) and 2V data retention capability, while the SA version uses higher standby current but is optimized for commercial/industrial speed-power trade-offs. Both use the same FP48 package.

Does the 7142SA55P support battery backup operation?

No - battery backup with 2V data retention is exclusive to the LA variants (e.g., 7142LA55P). The 7142SA55P is specified for full 5V operation only; applying 2V to VCC will not retain data and may cause undefined behavior. Its ISB3 standby current is 4 µA (max), significantly higher than the LA version's 1 µA, confirming its non-battery-optimized design.