Introduction
Who
Daniel Puratich Architecture & Management
Kenny Na EE Designer
What
A USB-C PD sink where we can select the output voltage with resistors
DNP and fitted resistors, should be foolproof 0805s
could be STUSB4500 - USB-C PD Sink IC
Intent for requesting 24V 65W when debugging https://uwarg-docs.atlassian.net/wiki/spaces/EL/pages/2701197313/RPi+Interface+Rev+C?atl_f=content-tree setup without the full drone
should support 12V and 5V as well for testing other boards, configured by soldering different resistors
Use a USB-C PD chip and the associated required FETs that are required for negotiation
Ideally does not require a microcontroller, due to cost constraints
USB-C input connector
XT30 output connector
don't worry about board area too much but it can be tiny
no buck converter
Resources
https://www.youtube.com/watch?v=W13HNsoHj7A&t=615s
https://hackaday.io/project/192576-picopd-usb-c-pd-30-pps-trigger-with-rp2040
https://www.ti.com/interface/usb/type-c-and-power-delivery/products.html#1241=PD%20controller&
https://www.usb.org/usb-charger-pd
Engineering
USB-C PD Controller Selection
Main Options
There were a few possible options that were selected from research:
https://www.digikey.ca/en/products/detail/stmicroelectronics/STUSB4500QTR/9092189
https://www.digikey.ca/en/products/detail/texas-instruments/TPS25730SRSMR/22147461
https://www.digikey.ca/en/products/detail/infineon-technologies/CYPD3177-24LQXQT/10238323
Cheap PMIC + RP2040 (ex. https://www.digikey.ca/en/products/detail/onsemi/FUSB302B10MPX/7356099 + https://www.digikey.ca/en/products/detail/raspberry-pi/SC0914-13/14306010?s=N4IgTCBcDaIEoAUwAYAsyQF0C%2BQ)
Decision Matrix
USB-C PD PMIC | Option 1 | Option 2 | Option 3 | Option 4 |
---|---|---|---|---|
Name | STUSB4500 | TPS25730 | CYPD3177 | FUSB302B + RP2040 |
Description | USB-C PD Sink IC | USB-C PD Sink IC | USB-C PD Sink IC | USB PD IC + MCU |
DigiKey $/ct | $5.22 CAD | $3.76 CAD | $3.51 CAD | $2.59 + $1.08 CAD |
Configuration | NVM config editing in EEPROM via I2C TPs | Strapping resistors on ADC pins | Strapping resistors on pins | Firmware control on RP2040 via I2C |
Misc. Pros | Popular and well documented USB-C sink device within hobbyist community | Newest controller, supports USB-C PD rev 3.1, simple to implement, extensive schem and layout guidelines | Cheapest option, simple implementation, some online examples | Most configurable option, no need for strapping resistor variants, completely firmware controlled via I2C |
Misc. Cons | Expensive | PD 3.1 is irrelevant for the purpose of this project, also doesn’t support 240W | Complicated implementation |