# Protecting reset pin from overvoltage

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 R1.

How can I protect my external controller? I need to limit the voltage it's seeing on BRD_RESET to VBUS and at the same time allow it to pull down BRD_RESET to GND