TUSB2046I: Connection Failure

Shinichi Yokota

Part Number: TUSB2046I

Hello,

An error appears on a host PC when the TUSB2046I is connected to it. No device is attached to any downstream port at this time. What could be the issue and how can it be fixed?

The both messages below imply that a large current could be running, however, current measurement confirms that there is no current flowing. Besides, the issue shows up on a different host PC.

The above message says, "Power Surge of USB Port – The unknown USB device requires more power than the one available on this port."

The next one says, "Power Surge of USB Port – The USB device is not working properly and exceeds the power limit of the hub port. Please remove this device."

Best regards,
Shinichi Yokota

over 1 year ago

0 David (ASIC) Liu over 1 year ago

TI__Guru*** 140065 points

Hi,

Can you please share the schematic? Is this a bus powered or a self powered design?

Thanks

David

0 Shinichi Yokota over 1 year ago in reply to David (ASIC) Liu

TI__Genius 9715 points

David,

I'll share the schematic off line.

Best regards,
Shinichi Yokota

0 David (ASIC) Liu over 1 year ago in reply to Shinichi Yokota

TI__Guru*** 140065 points

Yokota-san

Looking at the schematic, I see both BUSPWR and EXTMEM are floating. The design looks to be a bus-powered design, so the host is limiting the devices connected based on the expected maximum power it can provide (500 mA for the entire hub + devices). But for the bus-power mode, BUSPWR must be pulled to 3.3 V, and for the self-powered mode, it must be pulled low.

For the EXTMEM, when it is high, the serial EEPROM interface of the device is disabled. When it is low, terminals 5 and 6 are configured as the clock and data terminals of the serial EEPROM interface, respectively.

Thanks

David

0 Shinichi Yokota over 1 year ago in reply to David (ASIC) Liu

TI__Genius 9715 points

David,

The error didn't disappear when the BUSPWR pin and the EXTMEM pin were pulled up to 3.3 V. Besides, the error also shows up at a different USB port on the host PC.

Do you have any other hint?

Best regards,
Shinichi Yokota

0 David (ASIC) Liu over 1 year ago in reply to Shinichi Yokota

TI__Guru*** 140065 points

Yokota-san

Is there a way you can change from bus power to self power and see if the host is working with a self-powered hub?

Can you check the 48MHz clock and make sure it is running?

Can you also check the current that is being drawn by the VBUS?

Thanks

David

Interface

Interface forum

TUSB2046I: Connection Failure