Datasheet

USB 2.0 Hi-Speed Hub Controller
Datasheet
Revision 2.2 (02-17-12) 10 SMSC USB251xB/xBi
DATASHEET
Chapter 2 Block Diagram
Figure 2.1 USB251xB/xBi Hub Family Block Diagram
3.3 V
Upstream
PHY
Repeater
Controller
SCK
SDA
PHY#1
3.3 V
PLL
VDDA
VDDCR
Serial
interface
engine
Serial
interface
Port
controller
Port
power
USB data
downstream
Port
power
OC
sense
switch/
LED
drivers
USB data
downstream
Routing and port re-ordering logic
1.2 V reg
Bus-
power
detect/
V
bus
pulse
1.2 V reg
24 MHz
crystal
Upstream
USB data
To upstream
V
BUS
To I
2
C EEPROM or
SMBus master
PHY#x
Port #x
OC sense
switch driver/
LED drivers
TT
#x
TT
#1
...
Port #1
OC sense
switch driver/
LED drivers
OC
sense
switch/
LED
drivers
...
x indicates the number of available downstream ports: 2, 3, or 4