Infineon Technologies CY7C433-20JXCT

Overview

CY7C433-20JXCT from Cypress Semiconductor is a 4,096 × 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 advanced 0.65-µm CMOS technology, delivers 35 mA typical ICC1 at 20 MHz, and operates across industrial temperature range (–40°C to +85°C) on 5V ±10%. It serves as a depth-matched data buffer in UART-to-processor bridging and multi-clock domain synchronization.

For engineers reviewing the CY7C433-20JXCT datasheet, CY7C433-20JXCT pinout, CY7C433-20JXCT application, or CY7C433-20JXCT equivalent, key selection criteria include its 4K×9 depth, standalone retransmit functionality, HF/EF/FF flag timing behavior, and compatibility with IDT7204 and AM7204 in width-expansion configurations.

Technical Context

This FIFO implements dual-ported RAM architecture with separate read and write address pointers, enabling true asynchronous operation without internal arbitration. Its flag logic generates EF (Empty), FF (Full), and XO/HF (Expansion Out / Half Full) outputs based on pointer comparison, with HF valid only in standalone or width-expansion modes.

The device supports unlimited expansion: width expansion uses D0–D8 and Q0–Q8 bus stacking with shared R/W/MR control; depth expansion chains EF/FF/XO signals between devices while preserving 50 MHz throughput via parallel steering-no serial propagation delay penalty. Retransmit (RT) enables data replay without external logic when R and W are held HIGH.

Key Specifications

Pinout & Package

Package: 32-pin PLCC (Plastic Leaded Chip Carrier), 11.43 mm × 11.43 mm, JEDEC MS-026AC compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT7204L15TPG and AM7204-15JC, CY7C433-20JXCT uniquely supports hardware-level retransmit and offers tighter 20 ns access time at 50 MHz, making it optimal for error-resilient serial protocols where deterministic replay is critical.

Availability

CY7C433-20JXCT is available at Aetrix Electronics and suitable for industrial automation controllers, serial communication gateways, and FPGA configuration subsystems requiring stable component supply over extended product lifecycles.

Supply support for CY7C433-20JXCT 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 fabless semiconductor company specializing in programmable solutions for embedded systems, USB connectivity, and memory interfaces.

CY7C433 belongs to Cypress's legacy asynchronous FIFO product line, designed specifically for clock-domain isolation and burst-data buffering in industrial, telecom, and computing infrastructure where deterministic latency and flag-driven flow control are essential.

FAQ

What is the maximum operating frequency for independent read and write operations?

The CY7C433-20JXCT supports up to 50 MHz for both read and write operations independently. This is verified by its 20 ns access time (tA) and 20 ns cycle time (tRC/tWC) specifications under industrial conditions. The 50 MHz rating holds regardless of FIFO fill level-no performance degradation occurs as depth increases.

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

In depth-expansion mode, the XO/HF pin functions exclusively as Expansion Out (XO), not Half Full. It asserts LOW to enable the next FIFO in the chain when the current device reaches capacity. HF functionality is disabled in this mode and only active in standalone or width-expansion topologies per the logic block diagram and timing waveforms in Rev. *B datasheet page 8.

Can the CY7C433-20JXCT operate with mixed 3.3V and 5V logic interfaces?

No-CY7C433-20JXCT is strictly a 5V-only device. Its input thresholds (VIH = 2.0V min for commercial grade) and output drive levels (VOH = 2.4V min) are specified for 5V TTL compatibility. Interfacing with 3.3V logic requires external level-shifting circuitry; it lacks 3.3V-tolerant I/O or dual-supply capability.

Is retransmit functionality available when the FIFO is configured for width expansion?

Yes-retransmit (RT) remains fully functional in width-expansion configurations. The FL/RT pin retains its dual-mode behavior: when asserted LOW, it triggers retransmission of the most recently read data word across all stacked devices simultaneously, provided R and W are held HIGH per the functional description on page 2 of the datasheet.