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This device was built to function in auto-run mode, meaning that the end user can simply connect the USB-C port to a source and have a power to a load connected through the XT30. The board uses the USB-PD (Power Delivery) protocol to arbitrate its voltage and current with the source device.

NOTE: There are multiple board variants that arbitrate different voltage values. Check the silkscreen at the back of the board to view which voltage has been configured (circled with a marker).

The 20V, 15V and 12V boards are configured with a minimum of 3A and maximum of 5A current. This means that your source (wall power adapter) needs to be able to deliver the voltage circled on the silkscreen and a minimum of 3A current. This information is likely visible in fine print on the adapter.

The 9V board is configured with a minimum of 2A, and a maximum of 5A current. This means as low as an 18W power adapter (commonly shipped with smartphones) can work with this board.

NOTE: By default, all of the boards will draw 5V until PD arbitration is complete, due to dead battery mode. If your use case must avoid undervolting, connect the USB-C Sink device to the source, wait briefly, and then connect your device with the XT30.

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LEDs

To summarize the LED notes in the schematic:

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