Infineon Technologies CY7C4245V-25ASXCT

Overview

CY7C4245V-25ASXCT from Cypress Semiconductor is a 4K × 18-bit, 3.3 V synchronous FIFO memory with dual-clock asynchronous read/write operation, 67-MHz max clock rate (25 ns cycle time), 30 mA ICC, and 5 V-tolerant inputs. It implements programmable Almost Full/Almost Empty flags, retransmit function, and depth/width expansion capability for high-speed data buffering in communications interfaces and multiprocessor systems.

For engineers reviewing the CY7C4245V-25ASXCT datasheet, CY7C4245V-25ASXCT pinout, CY7C4245V-25ASXCT application, or CY7C4245V-25ASXCT equivalent, key selection criteria include its 4096-word depth, 18-bit bus width, synchronous flag timing control via VCC/SMODE, cascade-capable WXO/RXO pins, and STQFP-64 package compatibility with industrial temperature range operation.

Technical Context

The CY7C4245V-25ASXCT uses a dual-port SRAM array with independent read/write pointers, free-running RCLK/WCLK inputs, and synchronous flag generation updated exclusively on rising edges of RCLK (EF, PAE) or WCLK (FF, PAF). Its programmable offset registers (D0–D11) allow user-defined Almost Empty/Full thresholds, with default values of 127 words.

Depth expansion is implemented via WXI/WXO and RXI/RXO cascading signals, while width expansion shares control lines across parallel devices. The FL/RT pin supports both first-load daisy-chain initialization and standalone retransmit-resetting the read pointer to enable packet retransmission without external logic.

Key Specifications

Pinout & Package

Package: 64-pin 10 × 10 mm STQFP (thin quad flat pack), RoHS-compliant, industrial temperature range (–40°C to +85°C).

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72V2115L15PF and NB3N502MNG, the CY7C4245V-25ASXCT uniquely combines 4K depth, retransmit capability, and configurable synchronous flags - making it optimal for adaptive, cascade-aware, and packet-replay-critical designs where buffer margin and protocol resilience are non-negotiable.

Availability

CY7C4245V-25ASXCT is available at Aetrix Electronics and suitable for high-speed data acquisition systems, multiprocessor interconnects, serial-to-parallel protocol bridges, and industrial Ethernet node buffering requiring stable component supply across extended product lifecycles.

Supply support for CY7C4245V-25ASXCT 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 interface ICs for industrial, automotive, and communications infrastructure applications.

The CY7C42X5V family was engineered specifically for low-latency, dual-clock data buffering in mixed-voltage systems - emphasizing expandability, flag programmability, and robustness in real-time embedded data paths.

FAQ

What is the maximum supported clock frequency for CY7C4245V-25ASXCT?

The CY7C4245V-25ASXCT supports a maximum clock frequency of 40 MHz, corresponding to its –25 speed grade (25 ns minimum cycle time). This rating applies separately to RCLK and WCLK, which may operate asynchronously or be tied together. Exceeding 40 MHz violates timing specifications and risks metastability in flag updates and data capture.

How does the FL/RT pin function in standalone versus cascaded configurations?

In standalone mode, FL/RT operates solely as Retransmit (RT): a HIGH pulse resets the read pointer to the first physical location, enabling packet replay. In cascaded depth-expansion mode, FL selects device position - tied to VSS for the first device and VCC for followers - while RT functionality remains disabled. The pin's dual role is determined by system topology, not internal configuration.

Can PAE and PAF flags be used synchronously, and how is this configured?

Yes, PAE and PAF can operate synchronously by tying the VCC/SMODE pin to VSS (ground). In this mode, PAE transitions are synchronized to RCLK rising edges, and PAF transitions to WCLK rising edges - ensuring deterministic flag timing aligned with respective data paths. When VCC/SMODE is tied to VCC, both flags operate asynchronously with respect to clocks.

Is depth expansion limited to identical CY7C4245V-25ASXCT devices, or can different densities be cascaded?

Depth expansion requires identical density and speed-grade devices - e.g., only CY7C4245V-25ASXCT units may be cascaded together. Mixing densities (e.g., 2K + 4K) or speed grades (–15 + –25) violates pointer alignment, flag decoding, and timing margins. The WXO/RXO interface assumes uniform word depth and access timing across all devices in the chain.