USB
Review: USB-C Power Delivery Trigger Board (CH224)
Depending upon their capability, USB-C PD adapters and chargers can source a variety of different voltages and currents. This is typically 5V, 9V, 12V, 15V and 20V up to 100W (for PD version 3.0). The adapter will initially provide either 5V (to support legacy protocols) or no voltage at all (if USB-C PD only). To obtain 5V or a higher voltage, the sink device needs to request this. For USB Power Delivery, the mechanism is that the source (adapter) will advertise its capabilities through a series of PDO or power delivery objects and the sink will request the desired voltage …