Part Number: TPS65987D
My application is setup as follows:
The DFP is advertising 4 levels:
My assumption was the UFP would negotiated the highest power, which is 20V/1.5A.
If I unplug/plug the DFP many times, sometimes it will the UFP will choose 20V/1.5A, but 95% of the time it will choose 5V/3A.
I have tried manually grounding the input/output, 3V3, when un-powered, looking for some external state that might effect the behavior, but nothing changes the behavior.
I need to know:
Yes, you should be able to negotiate the highest power using configuration 3. I recommend reconfirming that it does choose that configuration because even a slight change in the ADCIN1 values could alter which configuration mode is chosen. One way to do this, is to connect the PD controller to the GUI and check the "Transmit Sink Capabilities" register to see if the Sink PDO's are configured properly.
I would also recommend tying VBUS1 and VBUS2 together instead of grounding VBUS2 as it states in the datasheet.
You mentioned that you are using a PD analyzer, could you please attach your PD logs as well?
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