Infineon Technologies CY7C4225V-15ASXCT

Overview

CY7C4225V-15ASXCT from Cypress Semiconductor is a 1K × 18-bit (1,024-word, 18-bit-wide), low-voltage synchronous FIFO memory with 3.3 V operation, 67 MHz maximum clock frequency, 15 ns read/write cycle time, and 5 V-tolerant inputs. It serves as a high-speed data buffer in asynchronous interface bridging between mismatched clock domains, supporting retransmit, programmable Almost Full/Almost Empty flags, and depth/width expansion.

For engineers reviewing the CY7C4225V-15ASXCT datasheet, CY7C4225V-15ASXCT pinout, CY7C4225V-15ASXCT application, or CY7C4225V-15ASXCT equivalent, key selection criteria include synchronous flag timing behavior (RCLK/WCLK-synchronized EF/FF), programmable offset register configuration, STQFP-64 package compatibility, and cascading support via WXO/RXO/FL pins for depth expansion.

Technical Context

The CY7C4225V-15ASXCT implements a dual-clock, 18-bit-wide FIFO using 0.65 µm CMOS technology with independent read (RCLK/REN) and write (WCLK/WEN) control paths. Its synchronous flag architecture ensures EF updates exclusively on RCLK edges and FF updates exclusively on WCLK edges, eliminating metastability in clock-domain crossing scenarios.

It supports three operational modes: standalone (single-device buffering), width expansion (parallel 18-bit buses), and depth expansion (daisy-chained cascading via WXI/WXO/RXI/RXO/FL). The VCC/SMODE pin selects asynchronous or RCLK/WCLK-synchronized PAE/PAF flag behavior, and the FL/RT pin enables retransmit functionality by resetting the read pointer to the first physical location.

Key Specifications

Pinout & Package

Package: 64-pin 10 × 10 mm STQFP (thin quad flat pack), RoHS-compliant, lead-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72V2115L15PF and NB3N502M, the CY7C4225V-15ASXCT uniquely combines dual-clock domain isolation, hardware retransmit, and depth-expansion capability-making it optimal for protocol-aware, expandable, and timing-critical buffering where deterministic recovery and scalability are mandatory.

Availability

CY7C4225V-15ASXCT is available at Aetrix Electronics and suitable for high-speed data acquisition, multiprocessor interfacing, and communications protocol buffering requiring stable component supply across industrial, test equipment, and embedded networking programs.

Supply support for CY7C4225V-15ASXCT 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.

The CY7C42X5V family was developed specifically for deterministic, low-latency data buffering in clock-domain-crossing scenarios-targeting test instrumentation, telecom infrastructure, and real-time embedded systems requiring reliable, expandable FIFO solutions.

FAQ

What is the function of the FL/RT pin in standalone versus cascaded configurations?

In standalone mode, FL/RT operates as Retransmit (RT): a HIGH pulse resets the internal read pointer to the first physical FIFO location, enabling hardware-accelerated packet replay. In cascaded depth-expansion mode, FL selects device hierarchy-tied to VSS for the first device and VCC for all followers-to configure proper cascade signal routing and initialization sequence.

How does the VCC/SMODE pin affect flag timing behavior?

When VCC/SMODE is tied to VSS, the PAE flag becomes synchronized to RCLK and the PAF flag to WCLK-ensuring deterministic, glitch-free transitions aligned with respective clock domains. When tied to VCC, both flags operate asynchronously, offering faster response but requiring external synchronization logic in safety-critical designs.

Can the CY7C4225V-15ASXCT be used in single-clock mode?

Yes. RCLK and WCLK may be tied together for single-clock operation, with REN and WEN controlling read/write enable timing. In this mode, the FIFO behaves as a standard synchronous FIFO with shared clock domain, retaining all status flags and programmable offsets-but losing true asynchronous domain isolation capability.

What is the default Almost Empty offset value for CY7C4225V-15ASXCT?

The default Almost Empty offset is 127 words, meaning the PAE flag asserts when 127 or fewer words remain in the FIFO. This value is stored in the internal 12-bit offset register and can be overwritten via LD/WEN-controlled programming cycles using D0–D11 during load mode.