PocketPD - USB-C Power Supply - HardwareV1.1

Description

This project utilizes PicoPD's previous work to prototype a bench power supply. Beside portable soldering iron, this should be one of the best portable tools for college electrical engineering students. This bench power supply is powered by USB-C PD 3.0/3.1 using their PPS capability. There is no buck or boost converter on the board. We will explore how to implement constant voltage (CV) and constant current (CC), two modes that are featured in all of the standard bench power supplies. Best of all, it will fit inside your pocket!

As the DIY community has grown, there are multiple ways to implement control features like adjusting parameters via Wifi, Bluetooth, or touch screen. We want to keep the design language simple, just physical knobs and buttons to control. This will give the system higher reliability when you need it to work.

Important note

Not all USB-C power supplies support Programmable Power Supply (PPS) but many modern charger/powerbank does. Through our small sample size that includes powerbank/charger from Anker, Ugreen, and Baseus, here is our recommendation for getting Constant Current mode out of the box:

• UGREEN 100W USB PD 3.0
• UGREEN 140W USB PD 3.1
• UGREEN 160W USB PD 3.1
• Anker 737 GaNPrime 120W
• Anker 737 PowerCore 24K

When using a source that doesn't support PPS, the software will enter 5V PDO profile and. Profile adjustment can be done by long press Volt/Amp button.

Hardware specification for HW1.1

• Input: 3.3V-21V @5A max USB-C
• Output: 3.3V-21V @5A max
• Connector: Banana jack or Detachable screw terminal
• RP2040 Micro-controller + 16MB of QSPI flash
• 5A - 23V max ideal diode load switch
• On board current/voltage sensor
• 0.96" OLED display over I2C
• Encoder and switches for user input

Note: All output connector tap on the same power rail.

Mechanical Specification

• PETG 3D printed case + encoder knob
• Operating temperature: 0°C - 80°C.

Device protection

At input

• TVS/ESD protection for CC/USB2.0/VBUS

At output

• TVS/ESD protection for VOUT
• Fly-back diode protection
• Reverse voltage protection
• Reverse current protection
• Short circuit protection

Libraries

• Hardware - GitHub
• Firmware - GitHub
• Updates - Hackaday