Renesas 7142SA35J

Overview

7142SA35J 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 35 ns maximum read cycle time (tRC), 5 V ±10% supply, and industrial temperature range (–40°C to +85°C) - used in real-time avionics data buffering and high-speed test equipment memory arbitration.

For engineers reviewing the 7142SA35J datasheet, 7142SA35J pinout, 7142SA35J application, or 7142SA35J equivalent, this page delivers verified timing parameters, BUSY input behavior, port-to-port arbitration constraints, and package-specific DC/AC electrical characteristics required for deterministic dual-port memory system design.

Technical Context

The 7142SA35J implements a true dual-port SRAM architecture with fully independent address, control, and I/O buses per port, enabling concurrent access without internal arbitration logic - unlike the MASTER IDT7132, it lacks on-chip arbitration and relies on external BUSY signaling from a MASTER device. Its BUSY pin functions solely as an input to inhibit writes during contention.

It supports two distinct power-down modes: TTL-level standby (ISB1/ISB2) and full CMOS-level standby (ISB3/ISB4), with typical active current of 80 mA and full standby current as low as 0.2 mA (LA variant); the SA variant exhibits 1.0 mA ISB3 at 25°C. All timing parameters are specified under AC test conditions with 3 V input swing and 30 pF load (100 pF for 55/100 ns versions).

Key Specifications

Pinout & Package

7142SA35J is supplied in a 48-pin Flatpack (FP48) package with ceramic body and side-brazed leads. Pin 1 is index-marked; all V_CC and GND pins must be externally connected per datasheet note requirements.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C133-35JC and AS7C3256B-35JC, the 7142SA35J uniquely provides dedicated BUSY-input behavior optimized for seamless integration with IDT7132 MASTER devices, enabling plug-compatible width expansion without additional logic - a capability absent in both alternatives.

Availability

7142SA35J is available at Aetrix Electronics and suitable for avionics data buffering, industrial motion control, and high-speed test equipment requiring stable component supply across extended production lifecycles and controlled obsolescence management.

Supply support for 7142SA35J 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, now part of Renesas Electronics since 2019.

The IDT7142 product line was engineered specifically for MASTER/SLAVE dual-port SRAM expansion architectures, delivering deterministic contention resolution and low-latency memory sharing in real-time embedded systems.

FAQ

What is the role of BUSY pins on the 7142SA35J?

The BUSYL and BUSYR pins on the 7142SA35J are dedicated inputs - not outputs - that accept active-low signals from a MASTER IDT7132 device. When either pin is driven LOW, the corresponding port's write operations are internally gated and inhibited, preventing data corruption during address contention. This behavior is fixed and cannot be reconfigured.

Can the 7142SA35J operate as a standalone dual-port RAM without a MASTER device?

Yes, the 7142SA35J can operate standalone with both BUSY inputs tied HIGH (via 270 Ω pull-ups), enabling full dual-port functionality. However, no hardware arbitration occurs - simultaneous writes to the same address on both ports will result in undefined data. System-level software or external logic must manage contention in standalone mode.

What is the maximum clock frequency supported by the 7142SA35J?

The 7142SA35J does not use a clock; it is an asynchronous SRAM. Its speed is defined by timing parameters: maximum read cycle time (tRC) is 35 ns, supporting up to 28.6 MHz sustained random access (1/35 ns). Write cycle time (tWC) is also 35 ns, with write pulse width (tWP) minimum of 25 ns.

Does the 7142SA35J support battery backup data retention?

No - only the LA variant (e.g., 7142LA35J) supports 2 V data retention. The 7142SA35J is the standard-power version and lacks battery backup capability; its ISB3 standby current is 1.0 mA (typ.), versus 0.2 µA for LA variants under data retention conditions.

Which packages are available for the 7142SA35J?

The 7142SA35J is available in 48-pin Flatpack (FP48), 48-pin LCC (LC48), and 48-pin DIP (PDG48/SB48) packages. The J suffix in 7142SA35J specifically denotes the FP48 package per IDT ordering conventions - confirmed by datasheet pin configuration diagrams and mechanical dimensions.