7

Application

The sections below are not part of the ST product specifications. They are intended to give a generic application

overview to be used by the customer as a starting point for further implementation and customization. ST does

not warrant compliancy with customer specifications. Full system implementation and validation are under the

customer’s responsibility.

7.1

General description

7.1.1

Power supplies

The STUSB1702 can be supplied in three different ways depending on the targeted application:

•

Through the VDD pin only for applications powered by VBUS that operate either in source power role

•

Through the VSYS pin only for AC powered applications with a system power supply delivering 3.3 V or 5 V

•

Through the VDD and VSYS pins for applications powered by VBUS with a system power supply delivering

3.3 V or 5 V. When both VDD and VSYS power supplies are present, the low power supply VSYS is selected

when VSYS voltage is above 3.1 V. Otherwise VDD is selected

7.1.2

Connection to MCU or application processor

The I²C interface is used to provide extensive functionality during system operation. For instance:

1.

Define the port configuration during system boot (in case NVM parameters are not customized during

manufacturing)

2.

Change the default configuration at any time during operation

3.

Adjust the port power capability in source power role according to contextual power availability and/or the

power partitioning with other ports

4.

Save system power by shutting down the DC-DC converter according to the attachment detection state

5.

Provide a diagnostic of the Type-C connection and the VBUS power path in real time

STUSB1702

Application

DS12664 - Rev 1

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