Adding Power Delivery

[FC1]

Hello.

1- We want to add USB Power Delivery to an existing converter which can deliver 2x 5.1 V/3A from an unique power stage (isolated converter with one transformer, one regulator IC, etc.).

The PD-controller has to meet the following requirements:

-Negotiate 5 V / 3A (only source power, dataless)

-Not interact with regulation, because we want only 5V output and we implement two independent outputs connected to one power stage

-Support BC 1.2

I know simple controllers from the past, that can do this job but they became NRND (I assume because they do not comply with latest PD 3.0).

New controllers look more complex and many features are not needed for our application (affecting costs as well).

Which solutions do you suggest for this application?

2- For another application, we want to implement USB Power Delivery on a DC/DC converter, non-isolated, to deliver 2x 5.1V/3A. We could add a PD-controller to an existing design or consider a re-design with a dedicated buck controller which includes Power Delivery. Input range: 8-26.5 VDC, operative temperature range: -25 °C – +55 °C.

Which solutions do you suggest for this application?

Thank you.

Regards,

FC1

[Daniele PRATI]

Regarding question 2, please have a look to our buck converter designed for power delivery and related dual port adapter solution

https://www.st.com/en/power-management/stpd01.html

https://www.st.com/en/evaluation-tools/steval-2stpd01.html

Best Regards

[Filippo Bonaccorso]

Hello FC1,

I totally agree with Daniele for item 2.

Why you need PD communication if you're providing only 5V? Are there any other reasons?

As regards application side, according to me, you have 2 option:

• PD Controller like STUSB4761 that can manage all power related PD communications
• STM32G0 + TCPP02 if you would like to use an MCU for your application and, thanks to TCPP02 you can interface 2 type-C ports. Do note that STM32G071 can have up to 2 PD interface.

I let you google to products information.

Feel free to comment/answare.

Filippo

[FC1]

Hello. Thank you very much for your replies.

I confirm that we want to source 2x 5V/3A from a DC/DC converter.

So, we could add a small controller to the existing design (preferred) or re-design using a new controller.

Our doubt is whether we need a PD-controller or a different controller compliant with USB Type-C like your TCPP02.

We know that a PD-device being charged tries to negotiate power with the charger (our unit). If negotiation fails, as example because the controller does not implement Power Delivery, the lowest voltage is passed (5 V, which is in any case the only voltage available from our unit). But we have to ensure that the device charges at full current (3A). It is not acceptable for our application that the charging current is set to lower value by the device (e.g. 0.9A) when the negotitation fails.

Your opinion?

We do not have a microcontroller on this particular unit, so we look for the simplest solution to enable charge.

Thanks again for your support.

Regards

[Filippo Bonaccorso]

Hello Again,

let me understand better so.

If you are a charger, so a source, you should be sure about your power; so I assume that there's no issue on source side.

Now you're reporting a "device" to be charged thus the application use case becomes unclear to me.

Can you clarify on the application?

If you're more comfortable, we could also discuss privately.

Let me know

Filippo