Infineon Technologies CY7C425-10JXCT

Overview

CY7C425-10JXCT from Cypress Semiconductor is a 1K × 9-bit asynchronous FIFO memory IC used for buffering data between mismatched clock domains or burst-to-continuous data streams. It supports independent 50 MHz read/write operations, features Empty (EF), Full (FF), and Half Full (HF) flags, and operates at 5V ±10% over commercial temperature range (0°C to +70°C). It is commonly deployed in UART bridging, video frame buffering, and legacy bus arbitration systems.

For engineers reviewing the CY7C425-10JXCT datasheet, CY7C425-10JXCT pinout, CY7C425-10JXCT application, or CY7C425-10JXCT equivalent, key selection criteria include its 10 ns access time, dual-port RAM architecture, retransmit (RT) capability in standalone mode, and compatibility with width/depth expansion topologies for scalable buffer depth.

Technical Context

This FIFO implements a dual-ported static RAM cell array with separate read and write address pointers controlled by asynchronous R and W strobes. Flag logic generates EF, FF, and HF outputs based on pointer comparison, with HF repurposed as Expansion Out (XO) in depth-expansion configurations.

The device uses TTL-compatible input thresholds (VIH = 2.0 V min, VIL = 0.8 V max) and drives outputs to VOH ≥ 2.4 V / VOL ≤ 0.4 V under load. Its 0.65 µm CMOS process ensures ESD protection >2000 V and latch-up immunity via guard rings and layout hardening.

Key Specifications

Pinout & Package

Package: 32-pin PLCC (Plastic Leaded Chip Carrier), 11.43 mm × 11.43 mm, body height 3.56 mm, lead pitch 1.27 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT7202L10J and AM7202-10JC, CY7C425-10JXCT offers lower dynamic power (35 mA vs. 45/40 mA), native retransmit support, and active-low EF/FF flags aligned with common FPGA IP core expectations-making it optimal for cost-sensitive commercial designs requiring debug replay capability.

Availability

CY7C425-10JXCT is available at Aetrix Electronics and suitable for UART bridge buffering, legacy bus arbitration, and video line buffering requiring stable component supply and long-term obsolescence management.

Supply support for CY7C425-10JXCT 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) is a U.S.-based semiconductor company specializing in programmable solutions, memory, and interface ICs for embedded and industrial systems.

The CY7C4xx FIFO family was designed specifically for high-reliability, low-latency data buffering in mixed-clock-domain systems where deterministic timing and expandability are essential-targeting communications infrastructure, test equipment, and industrial control.

FAQ

What is the maximum operating frequency for simultaneous read and write operations?

The CY7C425-10JXCT supports independent 50 MHz read and write operations, verified by t_RC = 20 ns and t_WC = 20 ns timing specifications. This allows concurrent full-speed data ingestion and egress without contention, provided setup/hold times (t_SD = 6 ns, t_HD = 0 ns) are met and clock skew remains below 3 ns.

Does CY7C425-10JXCT support 3.3 V I/O interfacing?

No. The device requires a 5 V ±10% supply and exhibits TTL-compatible thresholds (VIH ≥ 2.0 V, VIL ≤ 0.8 V), making direct connection to 3.3 V logic unsafe without level-shifting circuitry. Driving inputs above V_CC + 0.5 V or below GND may damage the part per Absolute Maximum Ratings.

How does the Half Full (HF) flag behave in depth-expansion mode?

In depth-expansion mode, the HF pin becomes Expansion Out (XO), asserting a delayed logic HIGH to indicate that the current FIFO is half-full and the next device in the chain should prepare for data acceptance. Its propagation delay (t_XOL/t_XOH = 10–25 ns) ensures synchronized handoff without race conditions across cascaded devices.

Can the Master Reset (MR) pin be used to clear only the write pointer while preserving read data?

No. MR is a synchronous global reset that clears both read and write pointers to zero, forces EF HIGH and FF LOW, and invalidates all stored data. There is no provision for partial pointer reset; alternative flow control must rely on EF/FF flag monitoring and selective R/W strobing.