The power for the interface MCU is routed through two load switches. One of the switches is for the VDD supply, and the other switch is for the USB supply. This enables the disconnecting of the interface MCU from the power domain when it is not in use.
Figure 1. Interface MCU power switch
These switches are controlled by the presence of a USB connected to the interface MCU USB connector J2 and the state of the nRF ONLY switch SW6. For more information, see Modes of operation.