General Description
The SMSC USB251xB/xBi hub is a family of low-power, configurable, MTT (multi transaction translator) hub controller IC products for embedded USB solutions. The x in the part number indicates the number of downstream ports available, while the B indicates battery charging support. The SMSC hub supports low speed, full-speed, and hi-speed (if operating as a hi speed hub) downstream devices on all of the enabled downstream ports.

FEATUREs
■ USB251xB/xBi products are fully footprint compatible with USB251x/xi/xA/xAi products as direct drop-in replacements
   — Cost savings include using the same PCB components and application of USB-IF Compliance by Similarity
■ Full power management with individual or ganged power control of each downstream port
■ Fully integrated USB termination and pull-up/pull down resistors
■ Supports a single external 3.3 V supply source; internal regulators provide 1.2 V internal core voltage
■ Onboard 24 MHz crystal driver or external 24 MHz clock input
■ Customizable vendor ID, product ID, and device ID
■ 4 kilovolts of HBM JESD22-A114F ESD protection (powered and unpowered)
■ Supports self- or bus-powered operation
■ Supports the USB Battery Charging specification Rev. 1.1 for Charging Downstream Ports (CDP)
■ The USB251xB/xBi offers the following package:
   — 36-pin QFN (6x6 mm) lead-free RoHS compliant package
■ USB251xBi products support the industrial temperature range of -40ºC to +85ºC
■ USB251xB products support the extended commercial temperature range of 0ºC to +85ºC

APPLICATIONs
■ LCD monitors and TVs
■ Multi-function USB peripherals
■ PC motherboards
■ Set-top boxes, DVD players, DVR/PVR
■ Printers and scanners
■ PC media drive bay
■ Portable hub boxes
■ Mobile PC docking
■ Embedded systems