6

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 compliance with customer specifications. Full system implementation and validation are under the

customer’s responsibility.

6.1

General information

6.1.1

Power supplies

The STUSB4500L can be supplied in three different ways depending on the targeted application:

•

•

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

up to 5 V

•

Through the VDD and VSYS pins either for applications powered by a battery with dead battery mode

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

When possible, please prefer VDD supply only, and connect it to VBUS in order to minimize application power

consumption. In this case, VSYS is not used and must be connected to GND.

6.1.2

Connection to MCU or application processor

The STUSB4500L connection to an MCU or an application processor is optional. However, an I²C interface with

an interrupt allows a simple connection to most of MCU and SOC of the market.

When a connection through the I²C interface is implemented, it provides an extensive functionality during the

system operation. For instance, it may be used to:

1.

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

manufacturing)

2.

Provide a diagnostic of the Type-C connection in real time

the default values from the embedded NVM. At power-up, the loading phase starts when the voltage level on the

VREG_1V2 output pin of the 1.2 V internal regulator reaches 1.08 V to release the internal POR signal. After a

reset, the loading phase starts when the signal on the RESET pin is released.

Power On Reset

VSYS or VDD

VREG_1V2

POR

1.08 V

Reset

VSYS or VDD

VREG_1V2

RESET

At power-up

After a reset

STUSB4500L

Application

DS13102 - Rev 1

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