The TUSB2046 is a 3.3 V CMOS hub device that provides one upstream port and four downstream ports in compliance with the 1.1 Universal Serial Bus (USB) specification. Because this device is implemented with a digital state machine instead of a microcontroller, no firmware programming is required. Fully compliant USB transceivers are integrated into the ASIC for all upstream and downstream ports. The downstream ports support both full-speed and low-speed devices by automatically setting the slew rate according to the speed of the device attached to the ports. The configuration of the BUSPWR pin selects either the bus-powered or the self-powered mode.