PocketPD is a tiny USB programable power supply created by Vincent Nguyen, along with Martin Axelsen and Ryan Trissel. The PocketPD is designed to be an ultra-portable bench power supply, utilising the power delivery standard. As we know most of our devices support power delivery, and this standard enables us to use the very same charger for all of our devices. Because of this, we don’t need to carry separate charges for each device and all we need is one PD charger with the maximum power rating we desire. As mentioned earlier the PocketPD is also designed by keeping this in mind. The PocketPD utilises the Programmable Power Supply(PPS) feature of USB PD 3.0 and 3.1 devices.
The PocketPD is built around the RP2040 SoC along with the AP33772 USB-PD controller. The RP2040 controls the AP33772 over I2C and when configured it will negotiate the corresponding voltage and current from the USB PD source. Since all the power controls are done within the source side the PocketPD doesn’t need any bulky inductors onboard. The board also contains onboard voltage and current sensors. A 0.96” OLED is used to display the information including set voltage/current, actual voltage /current and constant current and voltage modes. A rotary encoder and two tactile buttons are used to set the values and control the device. For output, the PocketPD has multiple connectivity options, such as an XT60 connector, banana jacks and a screw terminal. This enables us to use the PocketPD with any compatible connectors. The PocketPD is fully open-source and the firmware for it can be found in the PocketPD GitHub repository.
