/PWRON output of TUSB2046BIVFR is always inactive

John11513

Other Parts Discussed in Thread: AM3354, TUSB2046B

Hi,

A question about TUSB2046BIVFR: why its /PWRON outputs are always inactive (high) though all of its /OC inputs are high. The design is completely same as figure 13 schematic, self-powered hub, individual port power management configuraion. Could you please help to explain what is the possible cause that result /PWRON output always inactive?

Thank you,

John

over 10 years ago

0 Elias Villegas M. over 10 years ago

TI__Guru* 76130 points

Moving to the correct forum.

0 Elias Villegas M. over 10 years ago

TI__Guru* 76130 points

The PWRONn outputs are controlled by the USB Host, do you have a USB connection?
Can you share your schematic?

0 John11513 over 10 years ago in reply to Elias Villegas M.

TI__Expert 5720 points

Thank you for reply. The HUB has been connected to USB1 port of AM3354. Here is the schematic.

0 Joel Jimenez0 over 10 years ago in reply to John11513

TI__Mastermind 18655 points

Hello John,

Does your Hub meet the power-up requirement?, you should held RESET terminal it low during 100 µs to 1 ms at power up (when 3.3-V VCC reaches its 90%) and then release it.

The figure below shows an solution for the reset terminal that is used in our reference design.

Also, the TUSB2046B does not have internal pull-up resistors on the OVRCUR/ inputs and these are required.

Regards

0 John11513 over 10 years ago in reply to Joel Jimenez0

TI__Expert 5720 points

Hi,

Thank you. Yes, indeed power-up sequence not meet those requirement 100%. Actually the RESET is controled by CPU through a SPI-to-GPIO IC. RESET is high on power-up, after CPU running, application software issue a /RESET signal as long as 25ms. I am not sure is it meet the requirement?

Thank you!

John

0 John11513 over 10 years ago in reply to Joel Jimenez0

TI__Expert 5720 points

hi,

Have tested your proposed reset circuit, no effect.
For host side driver, they are using our demo, engineering name: AM335X_StartterWare_02_00_00_07

Thank you,
John

0 Joel Jimenez0 over 10 years ago in reply to John11513

TI__Mastermind 18655 points

Hello John,

Check the status of the SUSPND output. The TUSB2046B will go into the suspend state, and disable its /PWRON outputs, after no more than 10 ms of bus inactivity on all its downstream ports.

Provide a scope capture showing VCC, RESET, XTAL1 power up sequence.

Are the OVRCUR inputs pulled high?

Is the TUSB2046B being enumerated? or Is the customer getting an error message?

Regards.

Interface

Interface forum

/PWRON output of TUSB2046BIVFR is always inactive