Infineon Technologies CY7C4271-10JC

Overview

CY7C4271-10JC from Cypress Semiconductor is a 32K × 9-bit synchronous FIFO memory with independent read/write clocks, 10 ns access time, 100 MHz max clock frequency, and programmable Almost Empty/Almost Full flags. It serves as a high-speed data buffer in asynchronous communication interfaces between dissimilar clock domains, such as UART-to-processor bridging or DSP data acquisition subsystems.

For engineers reviewing the CY7C4271-10JC datasheet, CY7C4271-10JC pinout, CY7C4271-10JC application, or CY7C4271-10JC equivalent, key selection criteria include its dual-clock asynchronous operation, 32K depth with 9-bit width, programmable flag offsets, TTL-compatible I/O, and PLCC-32 package compatibility with IDT72201-series upgrades.

Technical Context

The CY7C4271-10JC implements a dual-port SRAM-based FIFO architecture with separate WCLK and RCLK domains, enabling true asynchronous read/write concurrency. Its flag logic is fully synchronous-EF and PAE update on RCLK edges, while FF and PAF update on WCLK edges-ensuring deterministic timing behavior across clock boundaries.

It supports two configuration modes selected at reset via WEN2/LD: either dual-write-enable for depth expansion or single-WEN1 + programmable flag offset loading. The 8-bit offset registers (defaulting to 007h for both empty and full thresholds) allow precise control of PAE/PAF assertion points down to single-word granularity.

Key Specifications

Pinout & Package

Package: 32-pin Plastic Leaded Chip Carrier (PLCC), JEDEC MO-047AC compliant, body size 11.43 mm × 11.43 mm, lead pitch 1.27 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72205L10JGI, CY7C4271-10JC offers native 5 V TTL compatibility and in-device flag programming, simplifying legacy system integration; unlike MC33880DW, it delivers dedicated high-depth buffering with deterministic asynchronous timing-making it irreplaceable in clock-domain bridging roles.

Availability

CY7C4271-10JC is available at Aetrix Electronics and suitable for industrial data acquisition, telecom line card buffering, and multi-processor interconnect applications requiring stable component supply and long-term obsolescence management.

Supply support for CY7C4271-10JC 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) designs high-performance mixed-signal ICs for embedded control, connectivity, and memory applications, with headquarters in San Jose, CA.

CY7C4271 belongs to Cypress's Deep Sync FIFO product line, engineered specifically for deterministic, low-latency data buffering across asynchronous clock domains in communications, test equipment, and real-time control systems.

FAQ

Is CY7C4271-10JC pin-compatible with CY7C4261-10JC?

Yes - both share identical 32-pin PLCC/TQFP footprints and signal mapping. The only functional difference is depth: CY7C4261-10JC provides 16K × 9 capacity versus 32K × 9 for CY7C4271-10JC. No PCB redesign is needed for density upgrade, and all control logic remains unchanged.

What happens if RS is not asserted before initial use?

Without reset, internal read/write pointers are undefined, causing unpredictable EF/FF flag states and potential data corruption. The device may output stale bus values or fail to assert EF even when empty. Cypress specifies mandatory RS pulse (≥10 ns) after power stabilization to initialize pointers to zero and guarantee empty-state behavior.

Can WCLK and RCLK be tied together for single-clock operation?

Yes - the datasheet explicitly supports tying WCLK and RCLK for synchronous operation. In this mode, the FIFO behaves as a standard clocked buffer with combined timing constraints; however, PAE/PAF flag update edges remain tied to their respective clock domains, so proper setup/hold margins must still be observed relative to the shared clock.

Does CY7C4271-10JC support hot insertion or live bus connection?

No - the device lacks hot-swap protection circuitry. Applying power while D/Q pins are driven risks latch-up due to back-powering through I/O clamps. Cypress recommends sequencing VCC before asserting any control signals and using series resistors on bidirectional buses to limit fault current during insertion.