Infineon Technologies CY7C4251-10AXI

Overview

CY7C4251-10AXI from Cypress Semiconductor is an 8K × 9-bit synchronous FIFO memory with TTL-compatible interfaces, 10 ns read/write cycle time, and programmable Almost Empty/Almost Full flags. It supports independent 100 MHz read/write clocks (RCLK/WCLK), operates at 35 mA ICC (commercial), and is used in high-speed data acquisition and multiprocessor interconnect buffering.

For engineers reviewing the CY7C4251-10AXI datasheet, CY7C4251-10AXI pinout, CY7C4251-10AXI application, or CY7C4251-10AXI equivalent, key selection criteria include synchronous dual-clock operation, 9-bit bus width, programmable flag offsets, and TQFP-32 package compatibility with IDT72241.

Technical Context

The CY7C4251-10AXI implements a dual-port SRAM-based FIFO architecture with separate RCLK and WCLK domains, enabling true asynchronous read/write operation. It uses synchronous flag logic-EF/PAE updated on RCLK edges, FF/PAF on WCLK edges-and includes dedicated offset registers for PAE/PAF thresholds.

It features two configurable write-enable modes: single-WEN1 control (for programmable flag operation) or dual-WEN1/WEN2/LD control (for depth expansion). The WEN2/LD pin serves as either second write enable or load control for 8-bit flag offset registers, with default empty/full offsets set to 7 words.

Key Specifications

Pinout & Package

32-pin Thin Quad Flat Package (TQFP), 7 mm × 7 mm body, 0.5 mm pitch, exposed pad not specified. Pin functions validated per Cypress Document #38-06016 Rev. *D.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72241L10PFI and NB3N502DG, CY7C4251-10AXI uniquely combines TTL compatibility, field-programmable flag thresholds, and dual-mode WEN2/LD for both expansion and configuration-making it optimal for retrofitting legacy systems requiring adaptive flow control.

Availability

CY7C4251-10AXI is available at Aetrix Electronics and suitable for high-speed data acquisition, multiprocessor interconnect, and communications protocol bridging requiring stable component supply and long-term obsolescence management.

Supply support for CY7C4251-10AXI 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) is a fabless semiconductor company specializing in programmable system-on-chip solutions, memory, and interface ICs for industrial, automotive, and consumer applications.

The CY7C42X1 product line was designed specifically for deterministic, low-latency data buffering in mixed-clock-domain systems-emphasizing synchronous flag reliability, expandability, and drop-in replacement capability for legacy FIFO designs.

FAQ

What is the default Almost Empty and Almost Full offset value for CY7C4251-10AXI?

The default Almost Empty and Almost Full offset values are both 7 words, stored across four 8-bit registers (empty LSB/MSB, full LSB/MSB). These values are factory-programmed and can be reconfigured via WEN2/LD-controlled write sequences on WCLK edges, with no external programming hardware required.

Can CY7C4251-10AXI operate with a single clock for both read and write?

Yes-RCLK and WCLK pins may be tied together for single-clock operation. In this mode, the device behaves as a standard synchronous FIFO with shared timing, while retaining independent REN1/REN2 and WEN1/WEN2/LD controls for precise gating of read/write actions on each clock edge.

How does the WEN2/LD pin determine FIFO configuration at power-up?

During reset (RS active-LOW), the logic state of WEN2/LD determines mode: HIGH configures dual-write-enable for depth expansion; LOW configures programmable flag mode and enables access to the four 8-bit offset registers. This configuration is latched and remains fixed until next reset.

Is CY7C4251-10AXI RoHS-compliant and Pb-free?

Yes-CY7C4251-10AXI is supplied in a Pb-free (lead-free) 32-pin TQFP package compliant with RoHS Directive 2011/65/EU. The "X" suffix in the part number explicitly denotes lead-free packaging, and the device meets JEDEC JS-001 ESD standards (>2000 V HBM).