CYPD3177 behavior and questions

[wiae_4532256]

Hi,

We are investigating a design which is a combination of cypress FX3 and CYPD3177.

As i understand from the knowledge base is that currently CYPD3177 does not support changing voltage/sink (PPS).

So we have to request the highest power needed from the beginning. Is that correct?

The FX3 can then read out the negotiated power.

I guess if the FX3 would afterwards change the power contract, the VBUS_FET_EN pin goes low and everything renegotiates from the start

If we want to make voltage and current dependable upon the application (run-time), we need to move to the CCG3PA?

Thanks

Wim

[ShifangZ_26 · Accepted solution]

Hi Wim,

1. You are correct that the BCR's request the highest power (Voltage * Current) based on power source PDO from Type-C Power Source and SINK PDO the BCR owned.

2. FX3 can change the power contract at running time. You can refer BCR HPI documentation to see what registers BCR have been defined to change the Sink PDO.

https://www.cypress.com/documentation/software-and-drivers/ez-pd-bcr-host-processor-interface-specif...​

Best Regards,

Lisa