We have an application we would like to power via USB PD. The device needs 12V or more to fully operate. To do a firmware upgrade 5V is sufficient. But the 5V are on a different Rail, normally supplied from the 12V Rail via DCDC converter. So we need a configuration which enables the 5V Rail if only 5V are available and disables the 12V Rail. Or if more than 12V are available disables the 5V Rail and enables the 12V Rail.
We thought about using the STUSB4500 and use the PowerOK2 pin to enable the 5V rail and the PowerOK3 Pin for the 12V Rail. But i have recognised that only the PowerOK2 Pin has the nessasary 20V rating for highside p-mos switching. This made me curious.
Why is this pin is different than sink enable or PowerOK2?
Are there any reference designs which are using the PowerOK pins?
EDIT: I have seen the eval kit now, seems to be nessasry to level shift, and supply with 2V7. How much current can be drawn from the 2V7 rail?
The device is functional with 12V but we would like to extract the maximum power from the source with upto 20V. Can this be requested? 12V 1A or more V and Amps. I have seen the request for maximum current, is there the same option for voltage?
Thanks for the help!
