PicoPD Pro - USB-C PD 3.1 PPS AVS with RP2040

We have completed most of the function that you will need to start your development with AP33772S based on PicoPD Pro. We have test the charger with UGREEN 140W and Framework 180W, both with 28V EPR support. We will release more documentation about the board shortly

AP33772S - GitHub

The library and IC was able to request and draw 3.6A at 30V. We only have a 8Ohm load for this test.

Here is the step voltage test from 15V to 30V using AVS mode with 1V increment. AP33772S allows the finest step in AVS as 200mV.

There is also some delay needed between each AVS profile, 600ms works very well in our application. When switching  between AVS mode and fixed PDO mode, we need a longer delay like 1200ms to ensure the request doesn't get ignore or cause a "hard-reset" from the charger.

Here are the profiles supported by the charger

The library basic functionality is almost completed. As you can see we now can switch between 30V in AVS mode to fix voltage profile at 15V and 9V. There is some bug that we will need to walk through like some sequence of transition can cause the system to hang and issue a hard power reset.

AVS profile require constant reminder from the sink for safety purposes. If there is no communication between the sink and source, the source will cut power and reboot at 5V. This is to ensure that if you drop your high voltage device into water, you will only get shock for a second or two. As the main IC fail, the communication will fail, and the power will be cut off.

Here are the 1st result of the first hardware test:

• Operational voltage of the 5V buck converter is 3.5V->30V
• 30 mins in mid air, 25°C room temp, 4.7A current pull result in max 66°C board temp
• Current reading is right on, +- 24mA accuracy

Booting up some basic code for the AP33772S, we were able to request 30V from Framework 16 charger. This is in AVS mode.

With 8 Ohm load, the current is 3.6A, pulling more than 100W.