Infineon Technologies CY7C4225-15AXCT

Overview

CY7C4225-15AXCT from Cypress Semiconductor is a 1K × 18-bit synchronous FIFO memory with TTL-compatible interfaces, 10 ns read/write cycle time at 100 MHz, 45 mA ICC (20 MHz), and programmable Almost Empty/Almost Full flags. It supports asynchronous dual-clock operation for buffering in high-speed data acquisition and multiprocessor interconnects.

For engineers reviewing the CY7C4225-15AXCT datasheet, CY7C4225-15AXCT pinout, CY7C4225-15AXCT application, or CY7C4225-15AXCT equivalent, key selection criteria include depth expansion capability via WXI/RXI/WXO/RXO pins, retransmit function for packet recovery, synchronous flag timing relative to RCLK/WCLK, and support for both standalone and cascaded configurations.

Technical Context

The CY7C4225-15AXCT implements a dual-port SRAM array (1024 × 18) with independent read and write pointers controlled by free-running RCLK and WCLK inputs. Its flag logic generates five synchronized status outputs - EF (RCLK-synchronized), FF (WCLK-synchronized), PAE/PAF (mode-selectable sync/asynchronous), and HF (shared with WXO).

Depth expansion uses daisy-chained WXO→WXI and RXO→RXI with FL pin configuration (VSS on first device, VCC on others); width expansion is supported via parallel 18-bit bus alignment. Retransmit (RT) resets the read pointer to enable deterministic packet replay without external controller intervention.

Key Specifications

Pinout & Package

Package: 64-pin TQFP (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 synchronous FIFO applications.

Compared with IDT72225L15PG and SN74V293-15PAG, the CY7C4225-15AXCT uniquely supports 3.3 V/5 V I/O flexibility, hardware retransmit for protocol resilience, and explicit FL pin control for reliable depth expansion - critical for industrial and communications systems requiring robustness and scalability.

Availability

CY7C4225-15AXCT is available at Aetrix Electronics and suitable for high-speed data acquisition, multiprocessor interconnect, serial protocol bridging, and industrial PLC I/O buffering requiring stable component supply across extended product lifecycles.

Supply support for CY7C4225-15AXCT 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 FIFO family targets high-reliability buffering applications demanding deterministic timing, expandable depth/width, and hardware-assisted protocol features like retransmit - optimized for real-time embedded subsystems.

FAQ

What is the default Almost Empty offset value for CY7C4225-15AXCT?

The default Almost Empty offset is 127 words. This value is stored in the internal 12-bit offset register and triggers the PAE flag when 127 or fewer words remain in the FIFO. It can be reprogrammed using the LD, WEN, and WCLK sequence described in the functional description - no external EEPROM or configuration memory is required.

Can CY7C4225-15AXCT operate with only one clock signal?

Yes. The RCLK and WCLK inputs may be tied together for single-clock operation. In this mode, read and write operations are time-multiplexed on the same clock edge, and the device behaves as a synchronous FIFO with shared timing constraints. All flag timing remains referenced to that single clock source.

How does the Half Full (HF) flag behave in depth-expanded configurations?

In depth-expanded configurations, the WXO pin functions exclusively as Write Expansion Out (WXO), not Half Full. The HF flag is disabled in cascade mode; only EF, FF, PAE, and PAF remain active. Half Full indication is not supported across multiple devices - system-level logic must derive aggregate fullness from individual device flags.

Is CY7C4225-15AXCT compatible with 3.3 V-only systems?

Yes. Although specified for 5 V operation, the CY7C4225-15AXCT supports 3.3 V logic levels on all I/O pins (D0–D17, Q0–Q17, control signals) when VCC = 5 V, due to TTL-compatible input thresholds and output drive strength. For pure 3.3 V supply operation, verify voltage tolerance per the Absolute Maximum Ratings table in the official datasheet.