Infineon Technologies CY7C4275-15ASC

Overview

CY7C4275-15ASC from Cypress Semiconductor is a 32K × 18-bit high-speed asynchronous FIFO memory with 100-MHz capability (10-ns cycle time), 5-V TTL-compatible I/O, and programmable Almost Empty/Almost Full flags. It supports independent read/write clocks, retransmit function, and depth/width expansion for buffering in high-speed data acquisition and multiprocessor interfaces.

For engineers reviewing the CY7C4275-15ASC datasheet, CY7C4275-15ASC pinout, CY7C4275-15ASC application, or CY7C4275-15ASC equivalent, key selection criteria include synchronous/asynchronous flag mode control via VCC/SMODE, cascading support using WXO/RXO/FL pins, and 64-pin TQFP packaging with center power/ground for noise reduction.

Technical Context

The CY7C4275-15ASC implements a dual-clock FIFO architecture with separate WCLK/REN and RCLK/WEN control paths, enabling true asynchronous read/write operation. Its status flags (EF, FF, PAE, PAF, HF) are synchronized to respective clocks-EF and FF to RCLK and WCLK respectively-ensuring deterministic timing behavior across clock domains.

Flag synchronization mode is selected by VCC/SMODE: tied to VSS enables synchronous PAE/PAF (PAE→RCLK, PAF→WCLK); tied to VCC enables asynchronous operation. The device supports depth expansion via WXI/WXO and RXI/RXO cascade signals, with FL pin configuration determining daisy-chain topology and first-load sequencing.

Key Specifications

Pinout & Package

64-pin 10×10 mm TQFP package with center power (VCC) and ground (GND) pins to minimize switching noise and improve signal integrity in high-frequency FIFO applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72225L15TPG and SN74V293-15PAG, the CY7C4275-15ASC uniquely combines 5-V TTL compatibility, configurable synchronous/asynchronous flag timing via VCC/SMODE, and integrated retransmit - making it optimal for industrial serial bridges and legacy-system upgrades where voltage and timing determinism are non-negotiable.

Availability

CY7C4275-15ASC is available at Aetrix Electronics and suitable for high-speed data acquisition, multiprocessor interconnect buffering, industrial serial protocol bridging, and communications line buffering requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for CY7C4275-15ASC 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 memory, microcontrollers, and programmable system-on-chip solutions for industrial, automotive, and communications markets.

The CY7C4275 belongs to Cypress' Deep Sync FIFO product line, designed specifically for deterministic, low-latency data buffering in mixed-clock-domain systems where metastability avoidance and precise flag timing are essential.

FAQ

What is the function of the VCC/SMODE pin on CY7C4275-15ASC?

The VCC/SMODE pin configures synchronization mode for the PAE and PAF status flags. When tied to VSS, PAE becomes synchronous to RCLK and PAF synchronous to WCLK - ensuring deterministic flag assertion timing relative to respective clocks. When tied to VCC, both flags operate asynchronously, reducing latency but introducing setup/hold uncertainty in multi-clock systems.

How does the FL/RT pin support retransmit functionality in stand-alone mode?

In stand-alone mode (non-cascaded), FL/RT operates as Retransmit (RT). Strobing this pin low for ≥60 ns causes the FIFO to output the last-read data word again on Q0–Q17 during the next RCLK cycle, provided REN is active and OE is low. This enables hardware-level frame recovery without CPU intervention after communication errors.

Can CY7C4275-15ASC be used in depth-expanded configurations, and what pins are required?

Yes - depth expansion uses WXO/HF and RXO outputs connected to WXI and RXI inputs of the next device in the chain. The FL pin of the first device must be tied to VSS; all subsequent FL pins tied to VCC. This configuration enables seamless stacking of multiple CY7C4275 devices while preserving flag timing integrity through controlled cascade signaling.

What is the minimum reset pulse width required for reliable initialization?

The minimum reset pulse width (tRS) is 15 ns at the RS pin for the -15 speed grade. A valid reset pulse must meet this specification to guarantee the FIFO enters a known empty state, with all internal pointers cleared and status flags (EF=LOW, FF=HIGH) correctly asserted before first read/write operations.