Renesas 7142LA100CB

Overview

IDT7142LA100CB from Integrated Device Technology (IDT) is a high-speed 2K × 8 dual-port static RAM configured as a slave device in master/slave memory expansion architectures. It features 100 ns maximum read/write cycle time, 5 V ±10% single-supply operation, industrial temperature range (–40°C to +85°C), and battery-backed data retention at 2 V - enabling use in fault-tolerant embedded controllers and real-time avionics interlocks.

For engineers reviewing the 7142LA100CB datasheet, 7142LA100CB pinout, 7142LA100CB application, or 7142LA100CB equivalent, key selection criteria include BUSY input functionality for port arbitration, low-power standby current (≤5 µA full CMOS standby), 48-pin flatpack package compatibility, and verified interoperability with IDT7132LA100CB as master in 16-bit+ width systems.

Technical Context

The 7142LA100CB implements independent left/right ports with separate address (A0–A10), control (CEL/CER, OEL/OER, R/WL/R/WR), and bidirectional I/O (I/O0–I/O7) lines, enabling fully asynchronous concurrent access. Its BUSY pin functions exclusively as an input-unlike the master IDT7132-which gates write operations when asserted by the master during address contention.

It uses CMOS process technology to achieve 325 mW typical active power and 1 µW typical full-CMOS standby (ISB3), with guaranteed 2 V data retention. The device supports both CE-controlled and R/W-controlled write cycles, with timing parameters including tWC = 100 ns, tWP = 55 ns, and tBDD ≤ 65 ns for port-to-port arbitration resolution.

Key Specifications

Pinout & Package

7142LA100CB is packaged in a 48-lead ceramic flatpack (FP48) with 0.75″ × 0.75″ footprint and 0.11″ height. Pin 1 is index-marked; all VCC (pins 24, 48) and GND (pins 1, 25) must be externally decoupled.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1371DV-100BZI and IS61WV20488BLL-100TQLI, the 7142LA100CB uniquely delivers 5 V TTL compatibility, integrated BUSY-input arbitration, and guaranteed 2 V data retention-making it irreplaceable in legacy industrial and safety-critical 5 V systems requiring zero-software-contention memory sharing.

Availability

7142LA100CB is available at Aetrix Electronics and suitable for real-time motor control, avionics data buffering, and industrial PLC I/O mapping requiring stable component supply across extended product lifecycles.

Supply support for 7142LA100CB 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

Integrated Device Technology (IDT), now part of Renesas Electronics, specializes in high-performance timing, memory, and interface solutions for communications, computing, and industrial markets.

The IDT7142 family was designed specifically as slave dual-port SRAMs to pair with IDT7132 masters in width-expanded memory systems-enabling error-free 16-bit+ word access without discrete glue logic.

FAQ

What is the function of the BUSY pins on the 7142LA100CB?

The BUSYL and BUSYR pins on the 7142LA100CB serve exclusively as inputs-not outputs-and are used to receive busy arbitration signals from a master IDT7132 device. When either BUSY pin is driven LOW (via external 270 Ω pull-up), the corresponding port's write operations are internally gated and inhibited. This prevents data corruption during simultaneous access to the same memory location, and is fundamental to the master/slave expansion architecture supported by the 7142LA100CB.

Does the 7142LA100CB support true 100 ns operation across its full industrial temperature range?

Yes, the 7142LA100CB is fully specified for 100 ns maximum read cycle time (tRC), write cycle time (tWC), and address access time (tAA) over the full industrial temperature range of –40°C to +85°C. These timing parameters are guaranteed per IDT datasheet revision May 2021, Table 08b and Table 09, and apply to both commercial and industrial grade versions of the 7142LA100CB part number.

Can the 7142LA100CB operate without a master IDT7132 in a standalone configuration?

Yes, the 7142LA100CB can operate as a standalone dual-port SRAM with both ports fully functional for independent read/write access. However, its BUSY pins must be held HIGH (via 270 Ω pull-up resistors) since they lack internal pull-ups and are not driven in standalone mode. In this configuration, hardware arbitration is disabled, and software-level conflict resolution becomes the system designer's responsibility.

What is the significance of the "LA" suffix in 7142LA100CB?

The "LA" suffix in 7142LA100CB denotes the low-power version with battery backup capability: it guarantees data retention at 2.0 V VCC and achieves ≤5 µA full-CMOS standby current (ISB3). This distinguishes it from the "SA" variant, which has higher standby current (≤15 µA) and no 2 V retention spec. The "CB" suffix indicates the 48-pin ceramic flatpack (FP48) package and industrial temperature grade.

How does the 7142LA100CB handle simultaneous read and write to the same address?

When both ports attempt access to the same address, the 7142LA100CB relies entirely on the external master IDT7132 to assert BUSY and gate one port's write. As a slave, the 7142LA100CB has no internal arbitration logic-it only responds to BUSY input. If BUSY is not asserted (e.g., in standalone use), simultaneous write to the same location results in undefined data; the device does not resolve contention autonomously.