Infineon Technologies CY7C4271-15AC

Overview

CY7C4271-15AC from Cypress Semiconductor is a 32K × 9-bit deep synchronous FIFO memory with dual-clock asynchronous operation, 10 ns read/write cycle time, 66.7 MHz maximum clock frequency, and programmable Almost Empty/Almost Full flags synchronized to RCLK/WCLK respectively - used in high-speed data acquisition systems requiring deterministic latency buffering between mismatched bus domains.

For engineers reviewing the CY7C4271-15AC datasheet, CY7C4271-15AC pinout, CY7C4271-15AC application, or CY7C4271-15AC equivalent, key selection criteria include flag synchronization timing, programmable offset register access sequence, width expansion compatibility, and PLCC/TQFP package pin mapping for PCB layout and signal integrity validation.

Technical Context

The CY7C4271-15AC implements a dual-port SRAM-based FIFO architecture with independent read (RCLK/REN1/REN2) and write (WCLK/WEN1/WEN2/LD) clock domains, supporting both single-clock and fully asynchronous operation. Its flag logic is strictly synchronous: EF and PAE update on RCLK edges; FF and PAF update on WCLK edges.

It features a 32K-word × 9-bit depth, 0.5 µm CMOS process, center-power/ground pin arrangement for noise reduction, and dual-mode WEN2/LD pin enabling either second write enable or programmable flag offset register loading - configurable at reset via LD pin state.

Key Specifications

Pinout & Package

32-pin PLCC (Plastic Leaded Chip Carrier) and 32-pin TQFP (Thin Quad Flat Package), both RoHS-compliant and Pb-free capable. Pinout identical across packages per Cypress Document #38-06015 Rev. *D.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72241L15PF and NB3N502DG, CY7C4271-15AC uniquely delivers field-programmable flag offsets, true dual-clock asynchronous operation, and width expansion - making it irreplaceable for adaptive buffering in mixed-signal and protocol-bridging designs where deterministic latency and runtime configurability are mandatory.

Availability

CY7C4271-15AC is available at Aetrix Electronics and suitable for high-speed data acquisition, multiprocessor interconnect buffering, and industrial serial interface bridging requiring stable component supply across extended product lifecycles.

Supply support for CY7C4271-15AC 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 fabless semiconductor company specializing in programmable system-on-chip solutions, memory, and interface ICs for industrial, automotive, and consumer applications.

CY7C4271-15AC belongs to Cypress's Deep Sync FIFO product line, engineered specifically for deterministic, low-latency data buffering across asynchronous clock domains in test equipment, communications infrastructure, and real-time control systems.

FAQ

What is the minimum pulse width required for the RS (Reset) signal?

The RS signal must be held HIGH for a minimum of 10 ns to ensure reliable reset initiation, and the device requires a falling edge on RS followed by tRSF (15 ns max) before EF becomes valid and Q0–Q8 stabilize to LOW. No read/write operations are permitted while RS is LOW, and the FIFO remains in undefined state until RS completes its cycle.

How do I configure the CY7C4271-15AC for programmable flag mode versus dual-write-enable mode?

Configuration occurs at power-up reset: if WEN2/LD is sampled LOW during RS assertion, the device enters programmable flag mode (WEN2/LD becomes LD pin); if sampled HIGH, it enters dual-write-enable mode. This state is latched and cannot be changed dynamically - mode selection is hardware-defined at boot.

Can the CY7C4271-15AC operate with WCLK and RCLK tied together?

Yes - tying WCLK and RCLK enables single-clock synchronous FIFO operation. In this mode, REN1/REN2 and WEN1/WEN2/LD remain independently controllable, allowing interleaved read/write cycles. Flag synchronization remains correct: EF/PAE track RCLK, FF/PAF track WCLK - which are now identical edges.

What happens to Q0–Q8 outputs when the FIFO is empty and additional reads occur?

When EF=LOW (empty), the CY7C4271-15AC holds the last valid output word on Q0–Q8 indefinitely - no bus contention or undefined states. Outputs remain stable until new data is written and a subsequent read occurs; OE control continues to function normally regardless of FIFO fill state.