•

the internal temperature returns below WTP range. In that case, the default contract is established

automatically.

The WTP range is a range between the WTP point and the OTP point.

When the temperature enters the WTP range an Alarm message is sent, but no other action is performed. Only

in case of new capability request or new contract, the next capability message limits the current/power, depending

on the setup on the configuration area. When the proposed capability is accepted the new power contract is

established. When the temperature exits from the WTP range and enters into normal range the next contract

returns to the default status.

9.1.7

USB-PD VCONN management

The VCONN is automatically provided by the device only during cable identification and before any explicit

contract is started. After the first capability message, the VCONN is removed.

9.1.8

PDO selection for multiport operation

The ST-ONEMP provides a dedicated power sharing function for multiport chargers. Depending on the level of the

GPIO1 pin, the ST-ONEMP provides two different PDO/APDO sets. The typical use of this function is to reduce

the available power on the main USB-PD port of the charger when a load is connected to a secondary port.

The level which determines the main or secondary PDOs to be used and the two PDO sets are programmable

through the configuration parameters.

The GPIO1 input can be filtered with independent deglitch filters for power sharing request assertion and

deassertion. This function can be useful for example when the second load detection is based on a current

threshold, avoiding repetitive changes on the primary port PDOs.

9.1.9

SVCC voltage change on cable detach

In USB-PD applications with multiple output voltage selection, the converter usually operates at lower efficiency

and limited power capability when the output regulated voltage is closer to the minimum. When no cable is

connected to the USB-PD output and the load switch is disabled, providing a voltage higher than 5 V can increase

the efficiency of the DC/DC converter for the second port if a consistent load is connected to it.

The ST-ONEMP can be configured to provide 9 V instead of 5 V when the Type-C cable is detached and the load

switch is turned off.

ST-ONEMP

USB-PD protocol

DS13989 - Rev 2

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