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Original question:

TUSB4020BI: Schematic review

TUSB4020BI: Schematic review

Pavel Skoda
Prodigy 100 points
Part Number: TUSB4020BI
Other Parts Discussed in Thread: TPS2561

Tool/software:

Hi Brian,

Thank you very much for reviewing my schematic, I have few more relating questions:

1. If I will not use SMBUS and I2C mode can I leave the TUSB4020B pin22 unconnected?

2. (See attached TUSB4020B pin21 question.pdfschematic please) - Why is the TUSB4020B pin21 pulled up (means active Low for power switching) when TPS2561 used in this Evaluation Module User Guide schematic is High enable?

3. Can I use the TUSB4020B part without additional SMBUS or I2C register settings?

Please let me know, thank you.

Pavel Skoda

  • 0
    TI__Guru*** 125930 points

    HI Pavel:

    Pavel Skoda said:
    If I will not use SMBUS and I2C mode can I leave the TUSB4020B pin22 unconnected?

    yes, SMBUSz can be floating if not use SMBUS and I2C mode.

    Pavel Skoda said:
    Why is the TUSB4020B pin21 pulled up (means active Low for power switching) when TPS2561 used in this Evaluation Module User Guide schematic is High enable?

       You need to set PWRCTL_POL pin based on power switch Enable pin. , PWRCTL_POL should be high if power switch  is low enable. PWRCTL_POL should be low if power switch  is high enable. 

       PWRCTL_POL has internal PD, on EVM when switch is on, PWRCTL_POL will be high with external Pullup. when switch is off. PWRCTL_POL will be low with internal pulldown.

    So EVM will have both PU and PD option.

    Pavel Skoda said:
    Can I use the TUSB4020B part without additional SMBUS or I2C register settings?

    Yes, TUSB4020B can work in default  register setting without any changes.

    Best

    Brian

  • +1 in reply to Brian Zhou
    Prodigy 100 points

    Hi Brian,

    Great, thank you so much for all your answers!

    I appreciate it a lot.

    Pavel