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TUSB2046B: TUSB2046 Current consumption

Shlomi Yehezkia
Mastermind 6150 points
Part Number: TUSB2046B
Other Parts Discussed in Thread: TUSB2077A

Hi Team,

Could you please advise the current consumption of the hubs for the following devices and configurations:

1.      TUSB2046 all ports active, High-Speed and Full-Speed.

2.      TUSB2077 all ports active ,High-Speed and Full-Speed.

Thanks,

Shlomi

  • 0
    TI__Guru 60870 points
    Hi Shlomi,

    TUSB2046 and TUSB2077 are Full-Speed only hubs. They do not support High-Speed operation.

    Current consumption for Full-Speed is as listed in the datasheet.

    Regards,
    JMMN
  • 0 in reply to JMMN
    Mastermind 6150 points

    Hi JMMN,

    I have a question regarding the design with the TUSB2077A:

    1. Does the 22pF capacitors at the data ports are recommended if all our USB devices are located on board with maximum DP/DM traces length of 20cm?

    2. If the TUSB2077A device is not powered (No VCC), does the DP0 and DM0 inputs have any load effect on the connected data line (D+, D-) of the USB? I’m planning to connect another USB device (Full-Speed) to these lines when the TUSB2077A is off and want to make sure this will not affect the USB connection.

    3. For the DP0PUR,if I use it as 3.3V connection for the pullup 1.5K resistor (as in the drawing) , if the TUSB2077A device is not powered (No VCC), does this pin is floating or it actually pull down the resistor?

    4. In section 7.3-Recommended Operating Conditions, the External series, differential driver resistor should be 22 Ohm, in Figure-9 the 27 Ohm is recommended and in the EVM TI use a 30 Ohm resistors, what is the bottom line?

    Thanks,

    Shlomi

    TUSB2077.docx

  • 0 in reply to Shlomi Yehezkia
    TI__Guru 60870 points
    Hi Shlomi,

    1. I believe the 22 pF caps were added for EMI, these are not required.
    2./3. The powered off characteristics of the TUSB2077A were not characterized.
    4. The 22 ohm series resistors are recommended by the USB specification. The idea is to create a 44 ohm termination when added to the source termination

    www.usb.org/.../usbfaq

    Regards,
    JMMN