USB3813 datasheet(17/57 Pages) MICROCHIP

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USB 2.0 Hi-Speed 3-Port Hub Controller Optimized for Portable Applications

Datasheet

 2014 Microchip Technology Inc.

DS00001715A-page 17

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

3.3V Regulator

The device has an integrated regulator to convert from VBAT to 3.3V.

4.1.2

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 18.

4.2.1

Single Supply Configurations

4.2.1.1

VBAT Only

VBAT must be tied to the VBAT system supply. VDD33 and VDDCOREREG must be tied together on

the board. In this configuration the 3.3V and 1.2V regulators will be active.

4.2.1.2

3.3V Only

VBAT must be tied to the 3.3V system supply. VDD33 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.

4.2.2

Dual Supply Configurations

4.2.2.1

VBAT + 1.8V

VBAT must be tied to the VBAT system supply. VDDCOREREG must be tied to the 1.8V system

supply. In this configuration, the 3.3V regulator and the 1.2V regulator will be active.

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