Infineon Technologies CY7C4225V-15ASC

Overview

CY7C4225V-15ASC from Cypress Semiconductor is a 1K × 18-bit (1,024 words × 18-bit) low-voltage synchronous FIFO memory IC with 3.3 V operation, 67 MHz max 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, such as in PCI-to-PCIe bridge subsystems or DSP-to-FPGA data pipelines.

For engineers reviewing the CY7C4225V-15ASC datasheet, CY7C4225V-15ASC pinout, CY7C4225V-15ASC application, or CY7C4225V-15ASC equivalent, key selection criteria include programmable Almost Full/Almost Empty flag offsets, dual-clock asynchronous read/write capability, depth/width expansion support, and synchronous flag timing behavior dependent on SMODE pin configuration.

Technical Context

The CY7C4225V-15ASC implements a dual-port SRAM-based FIFO architecture with independent write pointer (driven by WCLK/WEN) and read pointer (driven by RCLK/REN), enabling true simultaneous read/write operations. Its status flags-EF, FF, HF, PAE, PAF-are decoded from pointer positions and updated synchronously to respective clocks (RCLK for EF/PAE, WCLK for FF/PAF) when VCC/SMODE = VSS.

It supports retransmit (RT) functionality via FL/RT pin for packet-level data recovery, and depth expansion using WXI/WXO/RXI/RXO cascade pins with FL pin strapping logic. The device uses 0.65 µm CMOS process, features 30 mA ICC at 67 MHz, and provides three-state outputs controlled by OE.

Key Specifications

Pinout & Package

Package: 64-pin STQFP (10 mm × 10 mm, 0.5 mm pitch), RoHS-compliant, surface-mount.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72V2113L15PF and NB3N502M, the CY7C4225V-15ASC uniquely combines programmable flag thresholds, hardware retransmit, and true dual-clock domain isolation-making it optimal for protocol-aware, high-reliability buffering where deterministic latency and recovery autonomy are required.

Availability

CY7C4225V-15ASC is available at Aetrix Electronics and suitable for high-speed data acquisition systems, multi-processor interconnects, and communications protocol bridging requiring stable component supply across extended production lifecycles.

Supply support for CY7C4225V-15ASC 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 focus on reliability and integration.

The CY7C42X5V family was developed specifically for high-speed, low-latency data buffering in clock-domain-crossing scenarios-targeting telecom infrastructure, test equipment, and real-time imaging systems.

FAQ

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

The default Almost Empty offset is 127 words. This means the PAE flag asserts when 127 or fewer words remain in the FIFO. The offset can be reprogrammed via the LD/WEN/WCLK sequence to values between 0 and 255, allowing fine-grained flow control tuning for specific data rate mismatches.

How does the SMODE pin affect flag timing behavior?

When VCC/SMODE is tied to VSS, PAE and PAF become synchronous to RCLK and WCLK respectively-ensuring glitch-free flag transitions aligned to clock edges. When tied to VCC, they operate asynchronously, which may simplify timing closure in some legacy designs but introduces metastability risk in high-speed clock-domain crossings.

Can CY7C4225V-15ASC be used in single-clock mode?

Yes. WCLK and RCLK pins may be connected together for single-clock operation. In this configuration, the FIFO behaves as a synchronous FIFO with all timing referenced to one clock, simplifying PCB routing and timing analysis-but sacrificing the ability to absorb sustained read/write rate mismatches over long durations.

What is the purpose of the FL/RT pin in standalone mode?

In standalone mode (not cascaded), FL/RT functions as Retransmit (RT). A HIGH pulse on this pin resets the internal read pointer to the FIFO's first location, enabling hardware-triggered replay of buffered data-critical for packetized protocols where acknowledgment and retry are handled at the physical layer without CPU involvement.