USB251xB/xBi
USB 2.0 Hi-Speed Hub Controller
Datasheet
PRODUCT FEATURES
General Description
Features
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.
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
Highlights
High performance, low-power, small footprint hub
controller IC with 2, 3, or 4 downstream ports
Fully compliant with the USB 2.0 Specification [1]
Enhanced OEM configuration options available
through either a single serial I2C® EEPROM, or
SMBus slave port
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:
MultiTRAKTM
—
High-performance multiple transaction translator which
provides one transaction translator per port
—
36-pin QFN (6x6 mm) lead-free RoHS compliant
package
PortMap
—
Flexible port mapping and disable sequencing
USB251xBi products support the industrial
temperature range of -40ºC to +85ºC
USB251xB products support the extended
commercial temperature range of 0ºC to +85ºC
PortSwap
—
Programmable USB differential-pair pin locations ease
PCB design by aligning USB signal lines directly to
connectors
Applications
PHYBoost
—
Programmable USB signal drive strength for recovering
signal integrity using 4-level driving strength resolution
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
SMSC USB251xB/xBi
Revision 2.2 (02-17-12)
DATASHEET