TUSB2046BI issue with PWRON always high.

Dan Kendall

Other Parts Discussed in Thread: TUSB2046B

Hi.

I am testing the functionality of the TUSB2046BI, 4 port USB hub on a new board. The issue I am having is that PWRON1..4 are always producing a 3.3V signal. I have found that we are missing pull-ups on our OVERCUR1..4 singals, but after adding pullups, I didn't notice any change to PWRON. Any insight would be appreciated.

Thanks,

Dan K.

over 8 years ago

0 Joel Jimenez0 over 8 years ago

TI__Mastermind 18655 points

Hello Dan,

The PWRON# outputs are controlled by the USB Host, the TUSB2046BI receives from the Host the instruction to disable/enable the port in order to force the device enumeration.

Regards,
Joel

0 Dan Kendall over 8 years ago in reply to Joel Jimenez0

Prodigy 80 points

Thanks for the quick response. I will look into it.

Dan K.

0 vishwanath Shanbhag over 8 years ago in reply to Dan Kendall

Prodigy 40 points

Hi,

I have one more doubt here....Can we forcefully pull down POWERON# pins. What will be the response if we do so?

Regards,

Vishwanath Shanbhag

0 Joel Jimenez0 over 8 years ago in reply to vishwanath Shanbhag

TI__Mastermind 18655 points

Hello Vishwanath,

The USB host controls the port power of a USB hub using the SET PORT FEATURE (PORT POWER) and CLEAR PORT FEATURE (PORT POWER) commands, these commands cause the TUSB2046B to assert or dessert the PWRONz outputs. These commands are automatically by the USB driver loaded on the USB host. The power commands are sent during system power on / off, reboot, sleep and resume as needed. They will also be sent during overcurrent conditions. It is possible to generate these commands using another application, but it would likely require a custom USB driver to be used.

Regards,
Joel

0 Dan Kendall over 8 years ago

Prodigy 80 points

I found that the issue I was having was that the USB Host on the micro was not being powered properly. Once power was properly supplied the Host was able to send the appropriate commands to the TUSB2046BI to enable the ports.

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TUSB2046BI issue with PWRON always high.