TUSB2036: Not able to read anything on DP0 & DM0

Bhavya V

Intellectual 525 points

Part Number: TUSB2036

Attached is the schematic I put together on the new design.

R49 is DNP

After I connected USB cable to J4 I am not able to read anything on the USB port.

Mostly I don't see any device plugged into the computer.

After checking U9.P9,P13,P17 all the pins are pulled high.

U9.P10,P14,P18 are also help high.

Due to PWRON1 not turning low the data is not being passed along.

Can you please let me know what changes need to be made so U9 pull the PWR pin low?

over 2 years ago

0 Bhavya V over 2 years ago

Intellectual 525 points

Update here.

I realized J4.P2 and J4.P3 are switched. - fixed it.

Pulled BUSPWR to 3.3V

Now I see the USB being detected but with some error.

It maybe related to driver, but I am not sure will keep digging.

Meanwhile please let me know a fix.

0 Bhavya V over 2 years ago in reply to Bhavya V

Intellectual 525 points

I still see the PWRON pins of U9 being pulled high.

0 David (ASIC) Liu over 2 years ago in reply to Bhavya V

TI__Guru**** 178126 points

Hi,

Is this a self-powered or a bus-powered design? the BUSPWR is connected to a test point, it needs to be pulled high or low depending on whether the design is a bus-powered or a self-powered design.

You would also need to create RC reset circuit on the RESET pin. I would change R42 to a 1uF capacitor. You want to make sure the reset with a pulse width between 100 μs and 1 ms after 3.3-V VCC reaches its 90%. You also need to make sure the clock signal has to be active during the last 60 μs of the reset window.

Thanks

David

0 Bhavya V over 2 years ago in reply to David (ASIC) Liu

Intellectual 525 points

This resolved the issue

BUSPWR connected to 3.3V

R42 replaced with 1uF

Swapped DM & DP on J4

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TUSB2036: Not able to read anything on DP0 & DM0