I'm designing a board with a control port. The control port allows an external controller to reboot the system by pulling the
BRD_RESET low, effectively restarting both regulators.
However it is possible to use an external DC power supply (5-12V) instead of the USB bus voltage provided by the control port.
In this case I could fry my external controller (5V system) because the
BRD_RESET is pulled high to the external supply voltage (5-12V) by
How can I protect my external controller? I need to limit the voltage it's seeing on
VBUS and at the same time allow it to pull down