Power 101: The Versatility of USB Power Delivery Equipped Adapters

USB has lived up to being the Universal Serial Bus, even as it's evolved over the years. One of the benefits of USB is the power it provides to devices, and just as data rates have gone up, so too have power levels. The original USB 1.0 spec only allowed devices to drop to 500 milliamps at 5 volts. This increased over time, but with USB Type-C and Power Delivery 3.1, USB can now provide up to 240 Watts.

USB Power Delivery (or USB PD) is a specification that allows a USB connection to supply up to 5 amps at specific voltages from 5 to 20 Volts for the standard power range and up to 48 Volts for extended power range devices. This is enough to charge phones, tablets, and laptops, or to power larger devices such as monitors and TVs. The voltage and current level that a USB PD source provides is determined through a negotiation between the source and the load. The connection is initially made at 5 volts, with a 900 milliamp maximum current, to allow interoperability with legacy devices. The source then advertises its voltage and current capabilities and the load determines which configuration to use and requests it. If no communication occurs, or communication is lost, the source will provide the initial 5 volt 900 milliamp supply.

Adapters equipped with USB Power Delivery have the versatility to be used with a wide range of devices. This lets users carry fewer adapters and reduces e-waste, as adapters can be reused across many devices.