TUSB1002: USB 3.0 camera doesn't work

Ganea

Part Number: TUSB1002

Hello,

We have a USB 3.0 camera and when we connect it to our custom board it doesn't show any image.We don't have any oscilloscope capable of eye diagram measurement. And the correction with 220k resistors and 330nF were made. |When we connect the device it fallbacks to USB2.0.

This is the schematic:

System connections:

Laptop <== USB 3.0 1.8m cable ==> Custom board with TUSB1002 <== USB 3.0 1.5m cable ==> Camera

We have an 2GSps oscilloscope available. How would you measure USB 3.0 signal lines to check if the IC is working properly?

over 5 years ago

0 David (ASIC) Liu over 5 years ago

TI__Guru**** 150215 points

Ganea

Where do you place the 220k pulldown resistors?

Please also consider moving from TUSB1002 to TUSB1002A. If moving to 220A, then external 220k is no longer needed.

The schematic looks fine, what are your EQ, CFG, MODE, SLP_S0 setting? The best way to tune the setting is to look at the 10G USB signal, but a higher bandwidth scope is needed.

Can you please probe TX on both side of TUSB1002, are you at least seeing the LFPS signal? If you are seeing LFPS signal, please try shorter length of USB cable to see if it is a signal integrity problem.

Thanks
David

0 Ganea over 5 years ago in reply to David (ASIC) Liu

Prodigy 40 points

Hello David,

The LFPS signal is showing on the oscilloscope on the TX line like this:

MODE pin is floating

SLP_S0 pin is floating

EQ on 16 setting and CFG on 12 setting.

0 David (ASIC) Liu over 5 years ago in reply to Ganea

TI__Guru**** 150215 points

Ganea

The LFPS signal is a min of 10MHz and max of 50MHz signal, this looks more like a RX_DETECT, not LFPS, which means TX is not seeing far-end RX termination. Which side of TX are you measuring?

EQ of 16 is max equalizer, you may over-equalize the signal, please tune the EQ to a lower setting.But let's make sure we can see the CONNECT before focusing on the EQ tuning.

Where do you put the 220k pull-down termination?

Thanks

David

0 Ganea over 5 years ago in reply to David (ASIC) Liu

Prodigy 40 points

Thank you David, for your help. We've changed the chip to TUSB1002A and now the circuit works.

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TUSB1002: USB 3.0 camera doesn't work