3.3.2 External Supply
The Curiosity Nano+ Touch can be powered by an external voltage instead of the on-board target regulator. When the voltage off (VOFF) pin is shorted to ground (GND), the on-board debugger firmware disables the target regulator, and it is safe to apply an external voltage to the VTG pin.
Warning: Applying an external voltage to the VTG pin
without shorting VOFF to GND may cause permanent damage.
Warning: Absolute maximum external voltage is 5.5V for the
level shifters on board. Applying a higher voltage may cause permanent damage.
Programming, debugging, and data streaming are still possible while using external power. The debugger and signal level shifters will be powered from the USB cable. Both regulators, the debugger, and the level shifters are powered down when the USB cable is removed.