Infineon Technologies CY7C429-20JXCT

Overview

CY7C429-20JXCT from Cypress Semiconductor is a 2,048 × 9-bit asynchronous FIFO memory with independent 50 MHz read/write capability, TTL-compatible I/O, and dual flag support (Empty/Full/Half Full). It uses a dual-ported RAM cell architecture and supports width/depth expansion for system-level buffering in data acquisition and protocol bridging applications.

For engineers reviewing the CY7C429-20JXCT datasheet, CY7C429-20JXCT pinout, CY7C429-20JXCT application, or CY7C429-20JXCT equivalent, key selection criteria include its 2K×9 depth, 50 MHz max asynchronous throughput, standalone retransmit function, HF/EF/FF flag timing behavior, and PLCC-28 package compatibility with legacy industrial control interfaces.

Technical Context

This FIFO implements fully asynchronous read and write ports with no shared clock domain-each operates up to 50 MHz independently. The device features dedicated MR (Master Reset), FL/RT (Flag/Retransmit), and XO/HF (Expansion Out/Half Full) pins enabling flexible expansion topologies without serial propagation delay penalty.

It employs a 0.65-µm P-well CMOS process with >2000V HBM ESD protection and latch-up immunity. Flag logic is synchronous to respective control edges: EF asserts after final read, FF after final write, and HF transitions at exactly 1024 words filled-verified across all operating temperatures (–40°C to +85°C).

Key Specifications

Pinout & Package

Package: 28-pin Plastic Leaded Chip Carrier (PLCC), 11.43 mm × 11.43 mm, JEDEC MS-026AC compliant, lead-free option available.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT7203 and AM7203, CY7C429-20JXCT delivers superior timing precision (20 ns flag response), integrated retransmit functionality, and guaranteed HF flag accuracy at exactly 1024 words-making it optimal for deterministic real-time buffering where latency predictability and autonomous recovery are critical.

Availability

CY7C429-20JXCT is available at Aetrix Electronics and suitable for industrial serial bridges, legacy bus protocol converters, test equipment data capture, and motor drive feedback interfaces requiring stable component supply and long-term obsolescence management.

Supply support for CY7C429-20JXCT 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 programmable system-on-chip (PSoC), memory, and interface solutions for industrial, automotive, and consumer markets.

CY7C429 belongs to Cypress's legacy asynchronous FIFO product line, designed specifically for deterministic data buffering between asynchronous clock domains in industrial control, instrumentation, and communications infrastructure.

FAQ

What is the maximum sustained data rate supported by CY7C429-20JXCT?

The device supports independent 50 MHz read and write operations, enabling a sustained bidirectional data rate of 50 million 9-bit words per second per port. This translates to 450 Mbps aggregate throughput when both ports operate concurrently at maximum frequency, verified under industrial temperature conditions with proper decoupling.

How does the Half Full (HF) flag behave in depth expansion mode?

In depth expansion mode, the XO/HF pin functions as Expansion Out (XO), not Half Full. It asserts HIGH to signal the next FIFO in the chain that it should activate-enabling pipelined depth extension without cumulative propagation delay. The HF function is disabled in this configuration and only active in standalone or width-expansion topologies.

Can CY7C429-20JXCT operate with mixed voltage interfaces (e.g., 3.3 V logic driving W/R inputs)?

No-CY7C429-20JXCT requires TTL-compatible input thresholds: VIH ≥ 2.0 V (commercial) and VIL ≤ 0.8 V. Driving W/R with 3.3 V logic violates the absolute maximum input voltage rating (–0.5 V to +7.0 V) and risks latch-up. A level translator or resistor divider is required for safe interfacing with 3.3 V systems.

Is the retransmit (RT) function available when the FIFO is configured in depth expansion?

No-the retransmit function is only active in standalone or width-expansion configurations. In depth expansion, the FL/RT pin is repurposed as a flag select control and cannot initiate retransmission. Retransmit capability is inherently disabled when XO/HF is used for expansion signaling, as confirmed in the functional description on page 2 of Rev. *B datasheet.