Let's say I have an off-the-shelf power bank with USB-C PD, and it has 5V 3A, 9V 2A, 12V 1.5A options as output. If I used the CY4533 to negotiate 12 V, 300 mA, would that work?
Yes, it should work.
And if my load exceeded 300 mA, what would happen? Does the power bank handle the overcurrent or the CY4533 EZ-PD?
Ideally, the power bank is supposed to detect the overcurrent and act. CY4533 is not going to monitor current. It will monitor the incoming voltage and can raise an over-voltage flag, but not over-current.
Thanks for the clarification!