General Description

The SMSC 7-Port Hub is fully compliant with the USB 2.0 Specification and will attach to a USB host as a Full-Speed Hub or as a Full-/High-Speed Hub. The 7-Port Hub supports Low-Speed, Full-Speed, and High-Speed (if operating as a High-Speed Hub) downstream devices on all of the enabled downstream ports.

A dedicated Transaction Translator (TT) is available for each downstream facing port. This architecture ensures maximum USB throughput for each connected device when operating with mixed-speed peripherals.

The Hub works with an external USB power distribution switch device to control VBUS switching to downstream ports, and to limit current and sense over-current conditions.

All required resistors on the USB ports are integrated into the Hub. This includes all series termination resistors on D+ and D– pins and all required pull-down and pull-up resistors on D+ and D– pins. The over-current sense inputs for the downstream facing ports have internal pull-up resistors.

Throughout this document the upstream facing port of the hub will be referred to as the upstream port, and the downstream facing ports will be called the downstream ports.

PRODUCT FEATURES

■ Integrated USB 2.0 Compatible 7-Port Hub

— 7 Transaction Translators for highest performance

— High-Speed (480Mbits/s), Full-Speed (12Mbits/s) and Low-Speed (1.5Mbits/s) compatible

— Full power management with per port or ganged, selectable power control

— Detects Bus-Power/Self-Power source and changes mode automatically

■ Complete USB Specification 2.0 Compatibility

— Includes USB 2.0 Transceivers

■ VID/PID/DID, and Port Configuration for Hub via:

— Single Serial I2C EEPROM

— SMBus Slave Port

■ Default VID/PID/DID, allows functionality when configuration EEPROM is absent

■ Hardware Strapping options allow for configuration without an external EEPROM or SMBus Host

■ On-Board 24MHz Crystal Driver Circuit or 24 MHz external clock driver

■ Internal PLL for 480MHz USB 2.0 Sampling

■ Internal 1.8V Linear Voltage Regulator

■ Integrated USB termination and Pull-up/Pull-down resistors

■ Internal Short Circuit protection of USB differential signal pins

■ 1.8 Volt Low Power Core Operation

■ 3.3 Volt I/O with 5V Input Tolerance

■ 80-Pin TQFP lead-free RoHS compliant package