General description
The ISP1123 is a compound Universal Serial Bus (USB) hub device which complies with USB Specification Rev. 1.1. It integrates a Serial Interface Engine (SIE), hub repeater, hub controller, USB data transceivers and a 3.3 V voltage regulator. It has a configurable number of downstream ports, ranging from 2 to 5, with one port dedicated to an embedded or non-removable function.

Features
■ High performance USB hub device with integrated hub repeater, hub controller, Serial Interface Engine (SIE), data transceivers and 3.3 V voltage regulator
■ Complies with Universal Serial Bus Specification Rev. 1.1 and ACPI, OnNow and USB power management requirements
■ Downstream port 1 dedicated to a non-removable function, correctly reported in the related descriptors
■ Configurable from 2 to 5 downstream ports with automatic speed detection
■ Internal power-on reset and low voltage reset circuit
■ Supports bus-powered, hybrid-powered and self-powered application
■ Individual or global power switching for downstream ports
■ Individual or ganged port overcurrent protection with built-in sense circuits
■ 6 MHz crystal oscillator with on-chip PLL for low EMI
■ Visual USB traffic monitoring (GoodLink™) for hub and downstream ports
■ I2C-bus interface to read vendor ID, product ID and configuration bits from external EEPROM
■ Operation over the extended USB bus voltage range (4.0 to 5.5 V)
■ Operating temperature range −40 to +85 °C
■ 8 kV in-circuit ESD protection for lower cost of external components
■ Full-scan design with high test coverage
■ Available in 32-pin SDIP, SO and LQFP packages.