Infineon Technologies CY7C4225-10AXI

Overview

CY7C4225-10AXI from Cypress Semiconductor is a 1K × 18-bit synchronous FIFO memory with 10 ns read/write cycle time, 100 MHz clock operation, and TTL-compatible I/O. It supports independent asynchronous read/write clocks (RCLK/WCLK), programmable Almost Empty/Almost Full flags, and retransmit functionality-used in high-speed data acquisition systems requiring deterministic buffering between mismatched bus domains.

For engineers reviewing the CY7C4225-10AXI datasheet, CY7C4225-10AXI pinout, CY7C4225-10AXI application, or CY7C4225-10AXI equivalent, key selection criteria include its 18-bit width, 100 MHz timing margin, synchronous flag architecture, depth/width expansion capability, and industrial-grade temperature range (–40°C to +85°C) confirmed in Rev. *A of Document 001-45652.

Technical Context

The CY7C4225-10AXI implements a dual-port SRAM-based FIFO with separate read and write pointer logic, synchronized Empty/Full flags (EF updated on RCLK, FF on WCLK), and configurable PAE/PAF flags that operate synchronously when VCC/SMODE = VSS. Its retransmit (RT) function resets the read pointer to enable packet-level data replay without external controller intervention.

Depth expansion uses WXO/RXO cascading with FL pin sequencing (first device FL = VSS, others FL = VCC); width expansion connects multiple devices in parallel using shared clocks and enables. The Half Full (HF) flag shares the WXO pin and remains valid in standalone and width-expansion modes but serves as expansion output in depth-cascaded configurations.

Key Specifications

Pinout & Package

Package: 64-pin TQFP (10 mm × 10 mm, 0.5 mm pitch) - surface-mount, thermally efficient, and compatible with automated PCB assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72225L10PFI and MC100E126FNG, the CY7C4225-10AXI offers verified 5V TTL compatibility, industrial temperature rating, and integrated retransmit functionality - making it optimal for cost-sensitive, mixed-signal industrial systems where voltage and timing interoperability are primary constraints.

Availability

CY7C4225-10AXI is available at Aetrix Electronics and suitable for industrial data acquisition, multi-processor interconnect, and telecom line card buffering requiring stable component supply, long-lifecycle support, and guaranteed traceable sourcing.

Supply support for CY7C4225-10AXI 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 memory and programmable logic solutions for industrial, automotive, and communications markets.

The CY7C42X5 family was engineered specifically for deterministic, low-latency data buffering in asynchronous clock domain crossings - emphasizing reliability, expandability, and ease of integration in real-time embedded systems.

FAQ

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

In standalone mode, FL/RT operates exclusively as Retransmit (RT): a HIGH pulse resets the read pointer to enable packet replay. In cascaded depth-expansion mode, FL selects the first device in the chain (FL = VSS), while remaining devices use FL = VCC; RT functionality is disabled during cascade operation per Cypress Document 001-45652 Section 3.1.

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

When VCC/SMODE is tied to VCC, PAE and PAF operate asynchronously - their transitions depend on internal pointer comparison, not clock edges. When tied to VSS, PAE becomes synchronized to RCLK and PAF to WCLK, ensuring predictable setup/hold timing relative to read/write operations as specified in Table 2 of the datasheet.

Can CY7C4225-10AXI be used with non-50% duty cycle clocks?

Yes - the device supports free-running clocks with 40% to 60% duty cycle per Section 4.1 of the datasheet. However, minimum high/low times must meet t_WHL ≥ 3.5 ns and t_WLH ≥ 3.5 ns at 100 MHz operation; deviations outside this range risk invalid read/write cycles or flag metastability.

Is the Half Full (HF) flag available in all expansion configurations?

No - HF is available only in standalone and width-expansion modes, where it shares the WXO pin. In depth-expansion configurations, WXO functions as Write Expansion Out and HF is disabled; the Half Full status must be inferred from pointer positions or omitted from system logic per functional description on Page 4 of Document 001-45652.