TS3DV642: TS3DV642

Piet

Does the black screen go away if you are using a short cable at both the input and the output? 1080p@50Hz would be higher data rate and I want to see if signal integrity could be an issue here.

Thanks

David

Dear David,

The signals are:

• J1 input latest google Chromecast (length 10 cm).
• J2 output the TV (length 15 cm)
• J3 input Raspberry Pi 4 (length 15 cm)

Best Regards,

Piet

Piet

Is this the board trace length or the cable length?

Does the TV support 1080p@50Hz resolution?

Thanks

David

Dear David,

The answers:

The length that I mentioned is the cable length.

Yes, the TV supports many resolutions also 1080p@50Hz resolution.

When I connect the 2 devices directly to the TV on HDMI port 1 and 2 it looks fine!

Best Regards,

Piet

Piet

Any chance you can reduce the cable length and see if you are able to see the 1080p@50Hz resolution on the TV?

Thanks

David

Dear David,

No, that is not possible, because the length of the cables connected to the inputs and output is max. 15 cm!

Best Regards,

Piet

Piet

As an experiment, can we reduce the cable length? My concern is with the 1080p data rate, the total loss might be too much for the TV RX to compensate.

Thanks

David

Dear David,

I have no possibilities to make the cables shorter (10 - 15 cm)!

I ask the PCB engineer to make some screenshot about the design especial for the high speed one (see attachments).

Best Regards,

Piet

Piet

Can you share the actual layout file for review? Have you tried another TV and see if it works? I don't see an issue when looking at the schematic. TS3DV642 being a passive MUX would just pass through the video. But with it being a passive MUX, it would attenuate the signal quality.

Thanks

David

Dear David,

Yes, I tried another TV with the same results!

I attached the data how the PCB is buildup.

Best Regards,

Piet

Piet

Does this issue happen with the Chromecast and the Raspberry Pi 4 input or it happens when you are switching between the two inputs? What happens if you toggle the HPD from high to low, and then back to high again?

Thanks

David

Dear David,

I tested it before and when I used the Chromecast and on the other input the RPi 4. See below:

RPi 4 off and booting/startup Chromecast =>TV shows DVI 720x576 @ 50Hz and screen looks fine, but switching to HDMI 1080p @ 50 50Hz the TV goes black or after running both connectors out/in, no difference => TV black screen

Switch activated:

RPi 4 booting/startup and Chromecast off =>TV shows DVI 720x576 @ 50Hz and screen looks fine, but switching to HDMI 1080p @ 50 50Hz the TV goes black

I didn't test if the connections are made with the switch and then toggle the HPD line of the TV!  I will do that (today) by removing R1 and then toggle this line. 

Question: did calculate the difference impedance of the paired lines with the information I send to you? 

Best Regards, 

Piet

Piet

I assume this is Microstrip? Does the info below look correct?

Trace width: 7mil

Trace separation: 6mil

Trace thickness: ?

Dielectric thickness: 0.6mil

Dielectric constant: 3.9

Thanks

David

Dear David,

The requested information of the layer stack:

I assume this is Microstrip? Yes

Trace width: 7mil ? Is 7.9 mil

Trace separation: 6mil ? Yes

Trace thickness: ? 35um

See attached layer-stack.

Dielectric thickness: ? 0.6 mil  

Dielectric constant: ? 3.9

Best Regards,

Piet

Piet

Dielectric thickness is 10mil. With this, the calculated differential impedance is 113ohm.

Do you have a way to measure the clock frequency and eye diagram on the data lane at the TS3DV642 output?

Thanks

David

Dear David,

Strang's, we get different values when we calculated it with eCadStar or from you!

We had contact with the Zuken EMC Center in Paderborn and they are prepared to help us to solve the problem, but they need the S-parameter model from the TS3DV642A0RUAR. I will try to get the S-parameter form the RPi 4 so that they can simulate it. 

Can you help us to get the S-parameter from the TS3DV642A0RUAR.

Another question is of the layer stack from the PCB of the "TS3DV642EV MHDMI 1:2 Multiplexer and Demultiplexer Switch Evaluation Module" is available and are you willing to send us that information, so that we can calculate it with eCadStar.

Best Regards,

Piet

Piet

Please see this for the TS3DV642 s-parameter model.

https://e2e.ti.com/support/switches-multiplexers-group/switches-multiplexers/f/switches-multiplexers-forum/473446/ts3dv642-s-parameter-models-provided

For stackup, I sent you the board in a private message, would you please check and see if you received it?

Thanks

David

Dear David,

You send me the file named HVL074A.BRD, but I can't read it. Can you tell me with which tool I can open it?

Best Regards,

Piet

Dear David,

Yes, I received it and were trying to open this brd with the cadence viewer. see screenshot with error.

The design was made in version 16.5 and the viewer can't read it. Can you convert this file to the latest version of cadence so that we can read it (buildup stack)?

Thanks in advance.

Best Regards,

Piet

Piet

I sent you the updated board file in the private e2e message, would you please check?

Thanks

David