If you are into hardware hacking in any shape or form, having a handy power supply with which to power your latest prototype can be a real pain. Well, this tiny, USB-powered board can provide your project with up to 20 V! How are they pulling this off in such a tiny form factor?
With the release of USB Type C, the USB Implementers Forum created a standard called Power Delivery, which allows devices to charge at higher voltages and currents than the previous standards allowed for. Modern smartphones and laptops have started to take advantage of this, and are able to charge much faster due to the increased power available. Chargers which support Power Delivery can provide 20V at up to 5A (100W!) which is more than enough to charge the average laptop.
However, the charger won’t provide this extra power unless it is asked for, in order to maintain backward compatibility with older 5V-only USB equipment. To take advantage of this feature, you need a way to communicate with the charger over the new CC1 and CC2 lines in the USB-C cable. Once the attached device has asked for a higher voltage, the charger changes modes and delivers the requested voltage on the Vbus line. Not all chargers support all power levels, though. A charger can be Power Delivery compliant but only supply, say, 9 V at 3 A. This is plenty for the average smartphone, but just keep it in mind when you are choosing a charger to use with this board. So, the USB-C PD Sink is simply taking advantage of modern chargers with Power Delivery in order to provide a variable voltage power supply for whatever you want!
With just a compliant USB-C Power Delivery charger and the USB-C PD Sink, you can quickly and safely get enough power to keep all your projects moving! You can charge your quadcopter, or power your latest evil robot prototype — we won’t judge. The beauty of using a higher voltage is that you end up with less power dissipation in the cables, meaning more juice available for your project. It’s a win-win!
If you are interested in learning more about Power Delivery, the USB Implementers Forum has the full specification available on their website. It’s quite dense, and full of a lot of technical lingo, but it’s excellent that it’s freely available for us to learn from.