Infineon Technologies CY7C65621-56LTXI

Overview

CY7C65621-56LTXI from Infineon Technologies (formerly Cypress) is a 2-port, bus-powered USB 2.0 hub controller with single transaction translator (TT), integrated 24 MHz PLL, internal voltage regulator, and configurable SPI EEPROM support. It operates across –40 °C to +85 °C, supports high/full/low-speed USB devices, and integrates upstream pull-up and downstream pull-down resistors for BOM reduction. Used in compact peripheral hubs and embedded docking solutions.

For engineers reviewing the CY7C65621-56LTXI datasheet, CY7C65621-56LTXI pinout, CY7C65621-56LTXI application, or CY7C65621-56LTXI equivalent, key selection criteria include its 2-port bus-powered topology, single-TT architecture, 56-pin QFN package, EEPROM-based VID/PID/port configuration, and industrial temperature grade compliance.

Technical Context

The CY7C65621 implements a dedicated USB Serial Interface Engine (SIE) that handles bit stuffing/unstuffing, checksum generation/checking, TOKEN identification, and address checking independently of hub control logic. Its Hub Repeater manages same-speed connectivity (HS/FS/LS) between upstream and downstream ports, including suspend/resume and remote wakeup coordination.

Transaction Translator (TT) logic enables high-speed split transactions to full- or low-speed downstream devices, while routing logic dynamically selects TT or Repeater path based on attached device speed. Configuration is loaded at power-up from external SPI EEPROM, supporting runtime-defined VID/PID, port count, power settings, overcurrent timers, and indicator polarity.

Key Specifications

Pinout & Package

Package: 56-pin QFN (7 mm × 7 mm, 0.5 mm pitch), exposed thermal pad, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 2-port USB 2.0 hub controller applications.

Compared with USB2514B-AEZG, CY7C65621-56LTXI offers tighter integration for 2-port bus-powered use cases with zero-config EEPROM startup, while CY7C65620-56LTXI provides hardware compatibility at the cost of inflexible factory-programmed parameters.

Availability

CY7C65621-56LTXI is available at Aetrix Electronics and suitable for standalone peripheral hubs, monitor-integrated USB expansion, keyboard-embedded hubs, and industrial docking modules requiring stable component supply across extended temperature ranges.

Supply support for CY7C65621-56LTXI 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

Infineon Technologies acquired Cypress Semiconductor in 2020 and maintains the full EZ-USB portfolio, delivering mixed-signal ICs for connectivity, sensing, and power management.

The CY7C65621 belongs to the EZ-USB HX2LP Lite™ family-designed specifically for ultra-low-power, cost-sensitive USB 2.0 hub applications in space-constrained industrial and consumer peripherals.

FAQ

Does CY7C65621-56LTXI support self-powered operation?

No. The CY7C65621-56LTXI is strictly bus-powered and does not support self-powered mode. It draws all operating power from the upstream VBUS line and lacks the VBUS detection and power-path control circuitry required for self-powered operation-unlike the CY7C65631 or CY7C65640 variants.

What crystal frequency is required, and is it mandatory?

A 24 MHz fundamental-mode crystal is mandatory. The internal PLL uses this reference to generate all USB timing domains (480 MHz HS, 12 MHz FS, 1.5 MHz LS). No internal RC oscillator is provided; omission or substitution invalidates USB compliance and causes enumeration failure.

Can the number of active downstream ports be reduced below two?

Yes. Via SPI EEPROM configuration (0xD2 load), one or both downstream ports can be marked as "not removable" or "disabled" at boot. Disabled ports retain electrical termination but do not respond to SetPortPower or report status changes-enabling flexible single-port or dual-port deployment from identical hardware.

Is external overcurrent protection required, and how is it implemented?

Yes. CY7C65621-56LTXI provides OVR#[1]/OVR#[2] inputs and PWR#[1]/PWR#[2] outputs to interface with external power switches (e.g., TPS2051B). It does not include internal current-limiting FETs. Overcurrent detection relies on the external switch's fault signal routed to OVR#, with debounce time fully configurable via EEPROM (0–15 ms).