Infineon Technologies CY7C4291-10JXC

Overview

CY7C4291-10JXC from Cypress Semiconductor is a 128K × 9-bit synchronous FIFO memory with independent read/write clocks, programmable Almost Full/Almost Empty flags, and 100-MHz operation (10-ns cycle time). It supports asynchronous buffering in high-speed data acquisition, multiprocessor interfaces, and communications systems, featuring TTL-compatible I/O, output enable (OE), and center-power/noise-reduced PLCC-32 packaging.

For engineers reviewing the CY7C4291-10JXC datasheet, CY7C4291-10JXC pinout, CY7C4291-10JXC application, or CY7C4291-10JXC equivalent, key selection criteria include its 128K-depth × 9-bit width, synchronous dual-clock architecture, programmable flag offsets (default ±7 words), 2 mA standby current, and PLCC-32 mechanical compatibility with IDT72201-series FIFOs.

Technical Context

The CY7C4291-10JXC implements a dual-port SRAM-based FIFO with separate RCLK/WCLK domains, enabling true asynchronous read/write operation. Its flag logic is fully synchronous: EF and PAE update on RCLK edges; FF and PAF update on WCLK edges - eliminating metastability in clock-domain crossing.

It uses 0.5-µm CMOS technology with >2001 V HBM ESD protection and guard-ring latch-up prevention. The device supports flag offset programming via WEN2/LD in load mode, storing four 9-bit registers (empty LSB/MSB, full LSB/MSB) for precise buffer threshold control at single-word granularity.

Key Specifications

Pinout & Package

Package: 32-pin Plastic Leaded Chip Carrier (PLCC), JEDEC MS-026AC, body size 13.97 mm × 13.97 mm, lead pitch 1.27 mm, center power/ground pins for noise reduction.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar FIFO memory applications.

Compared with IDT72V2115L10PF and NB3N502DG, the CY7C4291-10JXC uniquely delivers 128K depth, 100-MHz operation, and field-programmable flag thresholds in a 5-V TTL-compatible PLCC-32 package - making it optimal for legacy industrial designs requiring flexible, high-capacity asynchronous buffering.

Availability

CY7C4291-10JXC is available at Aetrix Electronics and suitable for high-speed data acquisition, multiprocessor interfacing, and industrial protocol gateway applications requiring stable component supply and long-term obsolescence management.

Supply support for CY7C4291-10JXC 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

Cypress Semiconductor (now part of Infineon Technologies) is a U.S.-based semiconductor company specializing in memory, microcontrollers, and programmable logic solutions for industrial, automotive, and communications markets.

The CY7C4291 belongs to Cypress's Deep Sync FIFO product line, engineered specifically for deterministic, low-latency data buffering across asynchronous clock domains in mission-critical embedded systems.

FAQ

Is CY7C4291-10JXC pin-compatible with CY7C4281-10JXC?

Yes - both share identical 32-pin PLCC packaging and pinout. The CY7C4291-10JXC is a direct density upgrade (128K × 9 vs. 64K × 9) with identical timing, flag behavior, and control logic. No PCB redesign is needed when migrating from CY7C4281 to CY7C4291 for increased buffer depth.

How is the programmable Almost Full flag (PAF) configured?

PAF offset is set by writing to the Full Offset LSB/MSB registers via WEN2/LD in Load mode. With WEN2/LD held LOW at reset, four consecutive WCLK rising edges write values to empty LSB, empty MSB, full LSB, and full MSB registers. Default full offset is 7 words, making PAF assert when ≤131,065 words remain available in the 128K FIFO.

What happens if RS is asserted during active read/write operations?

Asserting RS forces the FIFO into a known empty state: EF goes LOW, all Q outputs go LOW after t_RSF, and internal pointers reset. However, data in transit or latched in input/output registers is lost. Cypress specifies that no reads/writes should occur while RS is LOW to guarantee reliable reset behavior and flag validity.

Does CY7C4291-10JXC support depth expansion?

No - depth expansion is not supported. The device supports only width expansion (e.g., 18-bit via two devices) using shared clocks and cascaded enable logic. Depth scaling requires external address management or a different FIFO family (e.g., CY7C42x5 series with depth-select pins); CY7C4291 has fixed 128K depth.