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I am using two of them to decide what source powers the board. One is a Wire to board terminal. The other is USBC.
We don't want the main rail to feed back into the USB connector. It can be anywhere between 9-20V. We want priority to come from the wire-to-board connector. (if it has >9V, let it take over regardless of the USB C power.
Any thoughts? Anything you would do differently?
Hi Richard,
Looks like you are designing a Priority Power Muxing Circuit with wire-to-board power supply as the first priority and the USB power supply being low-priority.
To realize Priority Power Muxing Circuit , you will need forward path ON/OFF control and reverse current blocking functionalities. LM74502 can do forward path ON/OFF control but can do reverse current blocking only when the FETs are turned OFF.
You will have to consider using LM7480-Q1 which has reverse current blocking feature and use it in power Muxing topology as shown below.
For more understanding on this topic, please refer to the below documents,
