Infineon Technologies CY7C4225-15AXC

Overview

CY7C4225-15AXC 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 operating current, and programmable Almost Empty/Almost Full flags. It serves as a high-speed data buffer in asynchronous communication bridges between processors, FPGAs, or ADC/DAC subsystems requiring deterministic latency and depth expansion capability.

For engineers reviewing the CY7C4225-15AXC datasheet, CY7C4225-15AXC pinout, CY7C4225-15AXC application, or CY7C4225-15AXC equivalent, key selection criteria include its dual-clock asynchronous operation, 18-bit bus width, retransmit function for packet recovery, and support for both width and depth cascading in industrial control and telecom interface designs.

Technical Context

The CY7C4225-15AXC implements a dual-port SRAM array (1024 × 18 bits) controlled by independent WCLK and RCLK inputs, enabling true simultaneous read/write operations without arbitration. Its flag logic includes synchronous EF (tied to RCLK) and FF (tied to WCLK), plus programmable PAE/PAF whose synchronization mode depends on VCC/SMODE pin state.

Depth expansion uses WXI/WXO and RXI/RXO pins with FL pin sequencing across daisy-chained devices; width expansion connects multiple units in parallel using shared clocks and enables while splitting the 18-bit bus. Retransmit (RT) resets the read pointer to enable repeat transmission of buffered packets without host intervention.

Key Specifications

Pinout & Package

Package: 64-pin TQFP (10 mm × 10 mm, 0.5 mm pitch) - compact surface-mount footprint compatible with high-density PCB layouts and automated assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72225L15PF and SN74V293-15PAG, the CY7C4225-15AXC uniquely integrates retransmit and Half Full flag in a single 64-pin TQFP package, reducing BOM count and improving packet reliability in mission-critical serial links without FPGA resource overhead.

Availability

CY7C4225-15AXC is available at Aetrix Electronics and suitable for industrial PLC communication bridges, high-speed data acquisition systems, FPGA-to-MCU protocol adapters, and telecom line card packet buffers requiring stable component supply over extended production lifecycles.

Supply support for CY7C4225-15AXC 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 global manufacturing and quality certifications including ISO 9001 and AEC-Q100.

The CY7C42X5 family was engineered specifically for deterministic, low-latency data buffering in multi-clock-domain systems - targeting industrial automation, test equipment, and communications infrastructure where jitter-free throughput is essential.

FAQ

What is the function of the VCC/SMODE pin on CY7C4225-15AXC?

The VCC/SMODE pin configures synchronization behavior of the Programmable Almost Empty (PAE) and Almost Full (PAF) flags. When tied to VSS (ground), PAE becomes synchronized to RCLK and PAF to WCLK - ensuring deterministic flag transitions aligned with respective clock domains. When tied to VCC, both flags operate asynchronously, which may introduce metastability risk in timing-critical reads but reduces clock dependency.

How does the retransmit (RT) feature work in standalone mode?

In standalone mode, pulsing RT high resets the internal read pointer to the first physical FIFO location. During retransmit, WCLK and RCLK must be disabled for tRTR (minimum 20 ns). Subsequent reads output previously written data sequentially until the read pointer equals the write pointer. This enables hardware-level packet replay without host CPU involvement or memory copy operations.

Can CY7C4225-15AXC be used in depth-expanded configurations with mixed densities?

No - depth expansion requires identical CY7C42X5 devices (e.g., all CY7C4225-15AXC) in the chain. Mixing densities (e.g., CY7C4225 + CY7C4235) violates pointer alignment and flag decoding logic, causing unpredictable Full/Empty assertion and potential data corruption. Only same-density parts guarantee correct cascade behavior per the FL pin sequencing rules.

What is the minimum setup/hold time requirement for WEN relative to WCLK?

WEN must be stable for ≥4 ns before the rising edge of WCLK (tENS = 4 ns) and held for ≥1 ns after (tENH = 1 ns) to ensure reliable write enable sampling. These values are specified in the -15 speed grade datasheet and apply across commercial temperature range; violating them risks metastable WEN capture and intermittent write failures.