Infineon Technologies CY7C4285-10ASC

Overview

CY7C4285-10ASC from Cypress Semiconductor is a 64K × 18-bit synchronous FIFO memory with 100 MHz operation (10 ns read/write cycle time), 5 V supply, and TTL-compatible I/O. It supports fully asynchronous dual-clock read/write, programmable Almost Full/Almost Empty flags, and retransmit functionality. Used in high-speed data acquisition systems requiring deterministic buffering between mismatched clock domains.

For engineers reviewing the CY7C4285-10ASC datasheet, CY7C4285-10ASC pinout, CY7C4285-10ASC application, or CY7C4285-10ASC equivalent, key selection criteria include depth expansion capability, synchronous flag timing control via VCC/SMODE, Half Full flag sharing with WXO, and cascading support using FL/RT, WXI/WXO, RXI/RXO pins.

Technical Context

The CY7C4285-10ASC implements a dual-clock FIFO architecture with independent RCLK and WCLK inputs, enabling true asynchronous operation. Its status flags (EF, FF, PAE, PAF, HF) are synchronized to respective clocks-EF and PAE to RCLK, FF and PAF to WCLK-ensuring deterministic timing behavior at boundary conditions.

Flag synchronization mode is controlled by the VCC/SMODE pin: tied to VSS enables synchronous PAE/PAF (RCLK/WCLK-aligned), while tied to VCC yields asynchronous operation. The device supports depth expansion via FL/RT, WXO/WXI, and RXO/RXI pins, with first-device FL = VSS and subsequent devices FL = VCC.

Key Specifications

Pinout & Package

64-pin 10×10 mm TQFP package with center power/ground pins for noise reduction and thermal performance. Pin layout optimized for signal integrity in high-speed clocked FIFO applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72245L10PFI and MC100E131FN, the CY7C4285-10ASC uniquely combines TTL compatibility, integrated retransmit, programmable flag synchronization, and standardized depth expansion-making it optimal for cost-sensitive, mixed-signal embedded systems requiring robust asynchronous buffering.

Availability

CY7C4285-10ASC is available at Aetrix Electronics and suitable for high-speed data acquisition, multiprocessor interconnect, and communications protocol buffering requiring stable component supply across commercial and industrial temperature ranges.

Supply support for CY7C4285-10ASC 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 programmable logic solutions for industrial, automotive, and communications markets.

The CY7C4285 belongs to Cypress's Deep Sync FIFO product line, engineered specifically for deterministic, low-latency data buffering across asynchronous clock domains in real-time embedded systems.

FAQ

What is the function of the VCC/SMODE pin on CY7C4285-10ASC?

The VCC/SMODE pin selects synchronization mode for the Programmable Almost Empty (PAE) and Programmable Almost Full (PAF) flags. When tied to VSS, PAE synchronizes to RCLK and PAF to WCLK; when tied to VCC, both operate asynchronously. This allows design flexibility for either deterministic flag timing or minimal latency in flag assertion.

Can CY7C4285-10ASC be used in single-clock mode?

Yes. The RCLK and WCLK inputs may be connected to the same clock source, enabling single-clock operation. In this configuration, the device behaves as a standard synchronous FIFO with shared timing, while retaining independent REN/WEN control and all status flags.

How does depth expansion work with multiple CY7C4285-10ASC devices?

Depth expansion uses WXO/WXI and RXO/RXI pins to daisy-chain devices. The first device has FL tied to VSS; all others have FL = VCC. WXO and RXO of each device connect to WXI and RXI of the next, forming a ring. Total depth equals sum of individual depths (e.g., two 64K devices yield 128K × 18).

Is the retransmit (RT) function available in cascaded configurations?

No. The FL/RT pin operates as First Load (FL) in cascaded mode and cannot perform retransmit. Retransmit is only functional in stand-alone or width-expanded configurations, where FL/RT is strobed low to repeat the most recently read data word on Q0–Q17.