3

Features description

3.1

PDO customization

The STUSB4761 implements a default configuration (cf section §4) stored in a non-volatile-memory (NVM)

and loaded at every power-ON. This configuration can be customized statically to align PD controller behavior

according to final application requirements. Customization applies to various parameters such as: number of

PDO, voltage, current, discharge time, protection thresholds, etc..

Parameter customization is possible:

•

Either by I²C interface direct access

•

Or by using specific commands packaged as ST proprietary unstructured VDM when the STUSB4761 is

connected in debug accessory mode (OrientedDebug Accessory.SRC state)

This process is recommended during end product manufacturing or testing. Once parameters have been

overridden in non-volatile-memory, it does not immediately apply. The STUSB4761 must be unpowered first and

new settings will apply after a power-on reset.

3.2

VCONN supply

The STUSB4761 features a 50 mA VCONN power switch with a fixed overcurrent protection (OCP) of 80 mA

typical.

3.3

E-marked cable support

The STUSB4761 can check a type-C cable current capability and clamp to 3 A any PDO that is not compliant with

the attached cable current ratings.

By default, passive cables support up to 3 A. If cable can support more than 3 A current, it must be marked

electronically (EMCA = Electronically Marked Cables Assembly).

Therefore, the STUSB4761 communicates directly with a type-C e-marked cable. This check is performed after

type-C attach and before starting a power negotiation. As a consequence, source power supply exposes any

PDO above 3 A only if cable is identified as able to sustain such current, otherwise PDOs are automatically

clamped to 3 A so that sink never receives erroneous information versus the application sustainability.

The device, which can sink up to 5 A from a capable source, would be notified 3 A max. in case the cable current

capability is not identified properly or not in line with the source capability.

3.4

Ambient temperature adaptive power and protection

The STUSB4761 embeds the temperature measurement and protection mechanism, used to prevent from

ambient overheating conditions. A dedicated pin (TSENSE) is used to sense PCB temperature measured by

an external NTC.

The STUSB4761 adjusts its USB PD output power (PDP) depending on temperature.

The temperature protection mechanism has 3 different thresholds, which can be adjusted with an appropriate

external resistor value (see Section 5.4 Reference schematic (full feature: up to 100 W, temperature adaptive

power, LED)).

STUSB4761

Features description

DS13141 - Rev 3

page 7/29