DS90UB954-Q1: Cuts in video image transmission

Adrian Palumbo

Part Number: DS90UB954-Q1
Other Parts Discussed in Thread: ALP, USB2ANY

Hi,

As I mentioned in the question asked a while ago, I largely solved the LOKC loss problem, proceeding to change the coaxial cables for another with better characteristics (DACAR 302).

https://e2e.ti.com/support/interface-group/interface/f/interface-forum/1000436/ds90ub954-q1-pattern-generator/3698814

Anyway, I still have some cuts, which are observed when the system starts. When some time passes, it stabilizes and works correctly.

Does anyone know where this problem may be generating?

Thank you.

over 4 years ago

0 Shruti More over 4 years ago

TI__Expert 6345 points

Hello Adrian,

Can you please run the MAP tool (Margin Analysis Program in the ALP software) and please provide us with the results?

Best Regards,

Shruti

0 Adrian Palumbo over 4 years ago in reply to Shruti More

Prodigy 40 points

Hello Shruti,

Thanks for the quick reply. I'm going to test if I can install it, because I have a Linux operating system.

Best Regards,

Adrian.

0 Shruti More over 4 years ago in reply to Adrian Palumbo

TI__Expert 6345 points

Hello Adrian,

Thank you. Link loss issues are related to signal integrity so a suggestion would also be to check the SI parameters, return loss, and insertion loss.

You can use ALP to connect to the FPD chip on your device, as long as you can establish the SCL and SDA (I2C pins) connection from your computer to the chip on your own board. There's typically an intermediary USB2ANY board that is needed to connect from the USB on your computer to the SCL and SDA pins on the FPD-Link chip.

Here are two application notes that can help you with the MAP tool in ALP:

https://www.ti.com/lit/an/snla301/snla301.pdf?ts=1631556436852&ref_url=https%253A%252F%252Fwww.google.com%252F

https://www.ti.com/lit/ug/snlu243/snlu243.pdf?ts=1631556438977&ref_url=https%253A%252F%252Fwww.google.com%252F

Best Regards,

Shruti More

0 Adrian Palumbo over 4 years ago in reply to Shruti More

Prodigy 40 points

Hi Shruti,

I don't have the resources to use the ALP, but reading the application notes that you gave me, I researched about the AEQ and I wanted to ask you:

What is the best way to configure it (AEQ Range, AEQ Timing, AEQ Threshold), if I have coaxial cables of a length between 4, 6 and even in some cases 15 meters?

Thanks and regards.

Adrian.

0 Shruti More over 4 years ago in reply to Adrian Palumbo

TI__Expert 6345 points

Hi Adrian,

We recommend using the AEQ feature as is with the pre-set registers. The adaptive equalization is meant to be automatic and the default register values are meant to provide correct functionality for AEQ. The only time we would suggest configuring the AEQ registers (software changes) is when the the PCB board layout/schematic is not meeting channel/datasheet specification for the FPD signals.

As for ALP, you can try an external USB2ANY and a laptop with windows.

If you want the python script with equivalent functions to the MAP tool/tab in ALP, you can down load ALP on a windows laptop then go to your C: drive:

C:\ALP\Analog LaunchPAD v1.57.0010\PreDefScripts\DS90UB954\ub954_margin_analysis_script

Hope this helps.

Best Regards,

Shruti

0 Adrian Palumbo over 4 years ago in reply to Shruti More

Prodigy 40 points

Ok Shruti, I understand the concept.

I'm going to see what I can do with the ALP tool.

Thank you!

0 Shruti More over 4 years ago in reply to Adrian Palumbo

TI__Expert 6345 points

Hello Adrian,

You are welcome!

Best Regards,

Shruti

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DS90UB954-Q1: Cuts in video image transmission