This is a board designed to use the USB C alternate modes to output DisplayPort and USB signals. While many adapters exist online, this was a good challenge to grow my knowledge in PCB design. It's designed on a 4-Layer board with proper impedance control for the USB and DisplayPort signals.
Please note that this is a board that is undergoing bringup currently, so this page is constantly being updated.
This project was designed to challenge my skills working with high speed devices, and modern protocols. While many USB C DisplayPort adatpers exist on the market, this was designed to help myself understand the USB C protocol better, and be able to negotiate the modes myself, which I would be unable to do with these off the shelf components. The TUSB1064 and STM32 were selected so that I had full control over the PD protocol, and design around a priority of DisplayPort signals, or a priority of USB signals. To add a unique twist on these adapters, I wanted to be able to have a dual-role power (DRP) board as well, that way this could be used in future projects.
The project was constrained to a small, 4 layer board, so that I could keep the scope small, and routing simple for highspeed lines. The 20V 5A requirement helped with learning power path designs as well, as there needed to be clear and simple paths for the higher voltages and amperages to follow, without impacting the highspeed signals.
| Board size | 49.4 mm x 55.1 mm x 0.8mm |
| Layer count | 4-layer, impedance-controlled |
| Power delivery | DRP, up to 20V @ 5A (sink and source) |
| USB signaling | USB 3.0 (SuperSpeed) (Routed at 90 Ohms) |
| DisplayPort | 2 or 4 lane configurable (Routed at 100 Ohms) |
| Fab/Assembly | Assembled by JLCPCB |
| CAD Software | KiCAD 10.0 |
| Parts count | 138 |
| Current revision | Rev 1 (in testing) |
Rev 1 - No official revision, current revision 1 is in testing
Rough Block Diagram of the Circuit
This is still a Schematic I'd like to clean up - this will be improved before completion
Top Silkscreen
Top Copper and Silkscreen
Top Copper
Internal GND Plane
Internal Power Plane
Bottom Copper
Bottom Copper and Silkscreen
Bottom Silkscreen
The full 3D board model isn't loaded automatically to keep this page fast.
Click-and-drag to orbit once loaded. Model file is served separately and only fetched on demand.
No instructions exist for this project, as the project is not yet complete. In addition, I do not plan on selling any, or providing files for this. This was a learning opportunity for myself, and it would take too much of my time to maintain files for others to make it.
Process Followed: Verified Placement under microscope, inspected solder joints. No solder bridges detected, and all components match the expected footprint pin indicator. Some connectors (barrel jacks) were left out due to part delays.
Process Followed:
Process Followed:
[Bring up process to be added]
[Bring-up photo and/or notes to be added]
Process Followed:
[Bring up process to be added]
[Bring-up photo and/or notes to be added]
[Bring up process to be added]
[Bring-up photo and/or notes to be added]
[Bring up process to be added]
[Bring-up photo and/or notes to be added]
The first board is suspected to have developed a bad regulator. The regulator appears to have a low resistance between the feedback and GND pins. The regulator appears to output a stable voltage, however does heats up much quicker. Further investigation pending, suspected to be due to rework from testing. Currently device is not being powered for excessive times, to prevent permanent damage on regulators.
No, currently this board being tested, I built this for myself to learn from, I have no interest in selling it. I plan on using all of the boards I've assembled.