Need help to get STUSB1602 working with PD compliant charger

[Vishnu Pratap Singh]

Posted on May 22, 2018 at 07:51

Hi,

We are using IMX7D SABRE based hardware with Linux4.1 BSP.

We have USB-PD compliant charge which can supply 12V 2A. Please let me how to ask USB-PD compliant charger to start supplying 12V-2A current. Should I be using USB-PD PDO's and send it to STUSB1602 over SPI line or are there any register setting which can be changed so that supply can be increased to 12V-2A configuration.

Please let us know if any more information is needed.

Currently we are blocked because of this.

Awaiting for your quick response.

[Gregory Go.]

Hello,

When you attach 2 USB Type-C applications together (1 Source to 1 Sink), it will always start with 5V output.

If 1 of both sides support only USB Type-C (i.e. not PD), the voltage on VBUS will stay at 5V.

But if both sides support USB PD (Power Delivery), you can get more voltage than 5V on VBUS (like 9V for instance)

Note that it is always the SINK side which request the Voltage&Current profile to the SOURCE:

1/ When you connect a USB-PD Device to a SOURCE, the SOURCE will send its power capabilities to the SINK.

2/ The Device (SINK) select one of the PDO profiles available, depending on how much power the Device needs.

3/ If the request is successful, the SOURCE provides the new power on VBUS.

In your case, if you use the STUSB1602 and you need 12V/2A from the Power supply, you need to configure the application software so that the STUSB1602 request the PDO 12V/2A.

Some code examples to request a specific PDO should be available in the STUSB1602 USB PD firmware: X-CUBE-USB-PD

To simplify the implementation of a PDO request in your application, you can use instead the STUSB4500 USB-PD controller, which can request automatically any desired PDO profile to a Power supply, without having to write any line of code.

Regards.