TUSB2046BIRHBRQ1 USB hub not detecting

vishwanath Shanbhag

Hi all,

I am using TUSB2046BIRHBRQ1 USB hub in one of our designs. But this hub is not getting detected. I have checked the interface which is coming as input to this hub and it is working. I have verified inputs like 3.3V VCC pins, Hub control signal and crystal of 6MHz frequency. Everything is fine . But still hub is not detecting any of the ports.

Please anybody help me in this regard.

Regards,

Vishwanath Shanbhag

over 10 years ago

0 Joel Jimenez0 over 10 years ago

TI__Mastermind 18655 points

Hello Vishwanath,

Please, share your schematics, we will review them and provide feed back as soon as possible.

The first step could be to review the power up sequence. The reset signal at power-up must be 1ms to 3ms long after the power supplies reached its 90%.

0 vishwanath Shanbhag over 10 years ago in reply to Joel Jimenez0

Prodigy 40 points

Hi joel,

Please find the schematic.. Please review it and suggest some solution.

Input to IC is the host USB.

Regards,

Vishwanatha RUSB_HUB.pdf

0 Joel Jimenez0 over 10 years ago in reply to vishwanath Shanbhag

TI__Mastermind 18655 points

Hello Vishwanatha ,

Terminals TSTPLL/48MCLK and TSTMODE must be tied to ground.

TheTUSB2046B does not have internal pull-up resistors on the OVRCUR/ inputs and these are required.

Regards

0 vishwanath Shanbhag over 10 years ago in reply to Joel Jimenez0

Prodigy 40 points

Hi joel,

Thank you for your input. I have tied pull up resistors on OVRCUR pins externally and even I have grounded TSTPLL/48MCLK and TSTMODE pins also as suggested by you. But still IC is not responding.

Have I missed anything else.

Regards,

Vishwanatha R

0 Joel Jimenez0 over 10 years ago in reply to vishwanath Shanbhag

TI__Mastermind 18655 points

Hi Vishwanatha,

Could you provide a scope capture showing VCC, RESET and XTAL2 signals at power up?

Regards

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TUSB2046BIRHBRQ1 USB hub not detecting