TUSB422: Converting from HDMI 2.0 to USB UVC

Hi John,

There is no specification that defines or supports anything past HDMI1.4 over type C. Trying HDMI2.0 over type C will not be supported by any PD controller.

We do have this guide for implementing HDMI1.4 over type C: https://www.ti.com/lit/an/slla333/slla333.pdf?ts=1738599946065&ref_url=https%253A%252F%252Fwww.google.com%252F

The reason it is very difficult to get HDMI over type-C is because the HDMI specification is DC coupled and the common mode for the signaling is 3.3V. The USB-C protocol is AC coupled and the common mode is at 0V. This means that an external biasing network will need to be added to bring the common mode to 3.3V at the transmitter for a valid HDMI sink to be detected. This external biasing network will be detrimental to signal quality. 

Is it possible for the customer to use DisplayPort, or convert the HDMI 2.0 to DP1.4 using an active protocol converter, and then sending the signal across USB-C?

Hi,

I'm closing due t inactivity.

Hi Vishesh,

Sorry for the delay, I just had a call with the engineer today 15 minutes ago. Do we have devices that can go from HDMI2.0 to CSI? So we can take the video data into a processor at TI? 

They need USB UVC because that is what the x86 processor they have can take in. Their processor doesn't have HDMI or DisplayPort video inputs. 

It sounds like we likely need to go HDMI to CSI - CSI into a TI AMxx processor - then processor output USB UVC

What do you think?

John

HI John,

Unfortunately, we do not have any HDMI to CSI converters. We Do have a HDMI to RGB solution but the maximum resolution is 1080p at 60 Hz. 

You can go from HDMI to LVDS using the full path, or HDMI to RGB using the half path. 

App note: https://www.ti.com/lit/an/slla325c/slla325c.pdf?ts=1738955243659&ref_url=https%253A%252F%252Fwww.ti.com%252Fsitesearch%252Fen-us%252Fdocs%252Funiversalsearch.tsp%253FlangPref%253Den-US%2526nr%253D7217%2526searchTerm%253Dhdmi+to+lvds