USB 2.0 HSIC Hi-Speed 4-Port Hub Controller
Datasheet
Chapter 4 Power Connections
4.1
Integrated Power Regulators
The integrated 3.3V and 1.2V power regulators provide flexibility to the system in providing power the
device. Several different configurations are allowed in order to align the power structure to supplies
available in the system.
The regulators are controlled by RESET_N. When RESET_N is brought high, the 3.3V regulator will
turn on. When RESET_N is brought low the 3.3V regulator will turn off.
4.1.1
4.1.2
3.3V Regulator
The device has an integrated regulator to convert from VBAT to 3.3V.
1.2V Regulator
The device has an integrated regulator to convert from a variable voltage input on VDDCOREREG to
1.2V. The 1.2V regulator is tolerant to the presence of low voltage (~0V) on the VDDCOREREG pin
in order to support system power solutions where a supply is not always present in low power states.
The 1.2V regulator supports an input voltage range consistent with a 1.8V input in order to reduce
power consumption in systems which provide multiple power supply levels. In addition, the 1.2V
regulator supports an input voltage up to 3.3V for systems which provide only a single power supply.
The device will support operation where the 3.3V regulator output can drive the 1.2V regulator input
such that VBAT is the only required supply.
4.2
Power Configurations
The device supports operation with no back current when power is connected in each of the following
configurations. Power connection diagrams for these configurations are included in Section 4.3, "Power
Connection Diagrams," on page 24.
4.2.1
Single Supply Configurations
4.2.1.1
VBAT Only
VBAT must be tied to the VBAT system supply. VDD33, VDDA33, and VDDCOREREG must be tied
together on the board. In this configuration the 3.3V and 1.2V regulators will be active. For HSIC
operation, VDD12 must be tied to VDDCR12.
4.2.1.2
3.3V Only
VBAT must be tied to the 3.3V system supply. VDD33, VDDA33, and VDDCOREREG must be tied
together on the board. In this configuration the 3.3V regulator will operate in dropout mode and the
1.2V regulator will be active. For HSIC operation, VDD12 must be tied to VDDCR12.
Revision 1.0 (06-17-13)
22
SMSC USB4604
DATASHEET
SMSC [ SMSC CORPORATION ]
