Infineon Technologies CY7C4205V-15ASXC

Overview

CY7C4205V-15ASXC from Cypress Semiconductor is a 256 × 18-bit, 3.3 V synchronous FIFO memory with 15 ns read/write cycle time, 67 MHz maximum clock frequency, and 5 V-tolerant inputs. It serves as a high-speed data buffer in asynchronous interface bridging between mismatched clock domains, supporting simultaneous read/write operations with programmable Almost Empty/Almost Full flags. Used in industrial communication gateways requiring deterministic latency and burst-mode buffering.

For engineers reviewing the CY7C4205V-15ASXC datasheet, CY7C4205V-15ASXC pinout, CY7C4205V-15ASXC application, or CY7C4205V-15ASXC equivalent, key selection criteria include its 256-word depth, synchronous flag timing control via VCC/SMODE, retransmit capability for packet recovery, and STQFP-64 packaging for space-constrained PCB layouts.

Technical Context

The CY7C4205V-15ASXC implements a dual-clock, 18-bit-wide FIFO using 0.65 µm CMOS technology with independent WCLK/REN and RCLK/WEN control paths. Its synchronous flag architecture ensures EF updates exclusively on RCLK edges and FF updates exclusively on WCLK edges, eliminating metastability in boundary-state detection.

It supports width expansion (parallel 18-bit buses) and depth expansion (daisy-chained cascading via WXI/WXO/RXI/RXO), with FL/RT pin enabling both first-load sequencing and standalone retransmit functionality. The VCC/SMODE pin selects between asynchronous (default) or synchronous (RCLK/WCLK-aligned) operation of PAE/PAF flags.

Key Specifications

Pinout & Package

Package: 64-pin STQFP (10 mm × 10 mm, 0.5 mm pitch), RoHS-compliant, lead-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72V2115L15PF and SN74V293-15PAG, the CY7C4205V-15ASXC uniquely combines programmable flag offsets, hardware retransmit, and depth expansion-enabling robust, scalable, and protocol-aware buffering in resource-constrained embedded systems.

Availability

CY7C4205V-15ASXC is available at Aetrix Electronics and suitable for industrial serial bridges, FPGA-to-microcontroller interfaces, packet-based communication gateways, and test equipment data acquisition requiring stable component supply across extended product lifecycles.

Supply support for CY7C4205V-15ASXC 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-reliability interface and memory ICs for industrial, automotive, and communications infrastructure markets.

The CY7C42X5V family was engineered specifically for deterministic, low-latency data buffering across asynchronous clock domains-targeting applications demanding guaranteed timing, programmable flow control, and hardware-assisted packet handling.

FAQ

What is the function of the VCC/SMODE pin on CY7C4205V-15ASXC?

The VCC/SMODE pin configures synchronization behavior of the Programmable Almost Empty (PAE) and Programmable 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, offering faster response but requiring external metastability mitigation.

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

In standalone mode, a HIGH pulse on the RT pin resets the internal read pointer to the first physical location of the FIFO, enabling immediate replay of all previously written data. During retransmit, WCLK and RCLK must be disabled for t_RTR (minimum 20 ns), after which reads resume from the start address-allowing hardware-level packet recovery without CPU intervention or register access.

Can CY7C4205V-15ASXC be used in depth-expansion configuration with other CY7C42X5V variants?

Yes-depth expansion is supported across the CY7C42X5V family using WXI/WXO/RXI/RXO pins. However, all devices in a daisy chain must share identical timing grades (e.g., -15 suffix) and voltage ratings. The FL pin of the first device connects to VSS; remaining devices connect FL to VCC. Mismatched densities (e.g., 256 × 18 + 512 × 18) are electrically valid but require careful flag decoding logic.

What is the minimum reset pulse width required on the RS pin after power-up?

The RS (Reset) pin requires a minimum pulse width of 10 ns to reliably initialize the FIFO to the Empty state (EF = LOW). A falling edge on RS must occur before any read or write operation, and the FIFO remains in reset while RS is LOW-ensuring predictable pointer alignment and flag states prior to normal operation.