• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 63 subscribers
  • Views 176 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TPS2511 - Cusb requirement

D. Johnson
Intellectual 700 points
Other Parts Discussed in Thread: TPS2511

The TPS2511 datasheet is very vague on the Cusb value / requirement.  The only reference is in the Layout Recomandations on page 20.

" Place the TPS2511 near the USB output connector and at lest 22-μF OUT pin filter capacitor. "

Also the Automotive charger reference design has no Cusb other than a small 0.1uF 

Question(s):

Is 22uF Cusb output required or suggested ? (by TI or USB Spec)

Thanks

Dave

  • 0
    TI__Intellectual 2795 points

    The USB 2.0 specification only requires 120uF total in the hub. In general, put 120uF on the output of every port, and it is not the mininum required.

    Due to cable inductance, there is undershoot when output happen hot-short and some output capacitance can help. 

    In addition, the bigger outpu cap also can help pass system level ESD test, so recommend 22uF output cap for TPS2511.

    Ask for one queson, why the automotive charger refence desin has no Cusb other than a small 0.1uF?