Datasheet
Table Of Contents
- Chapter 1 USB251x Hub Family Differences Overview
- Chapter 2 General Description
- Chapter 3 Acronyms
- Chapter 4 Block Diagram
- Chapter 5 Pin Descriptions
- Chapter 6 LED Usage Description
- Chapter 7 Battery Charging Support
- Chapter 8 Configuration Options
- Chapter 9 DC Parameters
- 9.1 Maximum Guaranteed Ratings
- 9.2 Operating Conditions
- Figure 9.1 Supply Rise Time Model
- Table 9.1 DC Electrical Characteristics (continued)
- Table 9.2 Supply Current Unconfigured: Hi-Speed Host (ICCINTHS)
- Table 9.3 Supply Current Unconfigured: Full-Speed Host (ICCINTFS)
- Table 9.4 Supply Current Configured: Hi-Speed Host (IHCH1)
- Table 9.5 Supply Current Configured: Full-Speed Host (IFCC1)
- Table 9.6 USB251x/xi/xA/xAi Supply Current Suspend (ICSBY)
- Table 9.7 USB251xB/xBi Supply Current Suspend (ICSBY)
- Table 9.8 USB251x/xi/xA/xAi Supply Current Reset (ICRST)
- Table 9.9 USB251xB/xBi Supply Current Reset (ICRST)
- Table 9.10 Pin Capacitance for USB251x, USB251xi, USB251xA, USB251xAi
- Table 9.11 Pin Capacitance for USB251xB and USB251xBi
- 9.2.1 Package Thermal Specifications
- Chapter 10 AC Specifications
- Chapter 11 Package Outlines

USB 2.0 Hi-Speed Hub Controller
Datasheet
SMSC USB251x 11 Revision 1.1 (04-26-10)
DATASHEET
Chapter 4 Block Diagram
Figure 4.1 USB251x Hub Family Block Diagram
Note 4.1 USB2512A/USB2512Ai only supports a single transaction translator.
Note 4.2 The LED port indicators only apply to USB2513/13i/14/14i (48QFN only) and USB2517/17i.
To Upstream
V
BUS
3.3 V
Upstream
PHY
Upstream
USB Data
Repeater
Controller
Serial
Interface
Engine
Serial
Interface
To EEPROM or
SMBus Master
SCL
SDA
Port
Controller
Bus-
Power
Detect/
V
bus
Pulse
PHY#1
USB Data
Downstream
OC
Sense
Switch/
LED
Drivers
USB Data
Downstream
Port
Power
3.3 V
PLL
24 MHz
Crystal
Routing & Port Re-Ordering Logic
Regulator
CRFILT
Port
Power
Regulator
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
...
The ‘x’ indicates the number of available downstream ports: 2, 3, 4, or 7.