CYUSB3304-68LTXC dribbling data in lookback and bench mark testing

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Chris_Hawthorne
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Hello!  I developed a USB 3.0 HUB based from the CY4609 RDK Board.  The first two runs of the boards worked well but the latest are dropping data sporadically on different down stream ports when tested as a USB 3.0 Hub.  I use Passmarks USB3 test plug to loop data through the HUB to make sure all is working well but a majority are having difficulties with failures during Bench Mark and Loop testing.  They fail at different points or will pass one time and fail the next.  It is really hard to try to half split to see what is going on.  I have some built on PCBs from the previous order and some that were built on this order.  Since the PCBs worked last time I don't think its a PCB issue so it must either be a component or manufacturing issue but with nearly every board failing I am at a loss.  

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MallikaK_22
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Hi,

Apologies for the delay. Yes, I've received the schematics. Please refer to my comments below:

>> Please ensure decoupling and bulk capacitors are present at the power pins as per Table 3 in the App Note .

>> Please check the crystal requirement as mentioned on Page 5 in the above App Note. I think the drive level of the crystal you are currently using doesn't match the required 200uW drive level. Kindly check.

The App Note has a schematic and layout checklist on Page 22. You may check that as well for reference.

Meanwhile, could you please let me know if you tried the swap test?

Regards,

Mallika

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MallikaK_22
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50 likes received 750 replies posted 250 solutions authored

Hi,

>> Could you please share your schematics if not confidential? 

>> If you confirm that the PCBs for both the good board and bad board is the same, would it be possible to do a swap test, i.e. replace the chip on the good board with the chip on the bad board and vice-versa. Kindly let us know if the failure follows the chip or the good board still behaved well even with the other chip.

Regards,

Mallika

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Chris_Hawthorne
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Hi Mallika!  Thank you for your quick response!  The schematics are confidential.  Is there a way to share them without openly posting them?  Also, I am working on swapping some components to see if that helps.  I'll keep you posted, let me know how to get you the schematic!

Chris

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MallikaK_22
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50 likes received 750 replies posted 250 solutions authored

Hi Chris,

Kindly share it at mallika.khare@infineon.com

 

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Hi Mallika!

I sent the schematics to your email 9/14/2021.  If you didn't receive let me know and I will resend them.

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MallikaK_22
Moderator
Moderator
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50 likes received 750 replies posted 250 solutions authored

Hi,

Apologies for the delay. Yes, I've received the schematics. Please refer to my comments below:

>> Please ensure decoupling and bulk capacitors are present at the power pins as per Table 3 in the App Note .

>> Please check the crystal requirement as mentioned on Page 5 in the above App Note. I think the drive level of the crystal you are currently using doesn't match the required 200uW drive level. Kindly check.

The App Note has a schematic and layout checklist on Page 22. You may check that as well for reference.

Meanwhile, could you please let me know if you tried the swap test?

Regards,

Mallika

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Chris_Hawthorne
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Hi Mallika!  I do apologize for the delay.  I had to send the boards back to the assembler to remove the parts.  I am still waiting for them to return them.  I did find in the app note that there was an issue with the oscillator I substituted and I am hopeful this will fix the issue I was having.  As soon as the boards return I will test them and let you know.

Best Regards,

Chris 

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Chris_Hawthorne
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Hi Mallika!  I received the boards back and changing the oscillator seemed to really help.  Thank you for your help!

Best Regards,

Chris

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