• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 63 subscribers
  • Views 359 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.

LM5164: Output capacitor and series resistance Resr

Lorenzo Morri
Intellectual 410 points
Part Number: LM5164

Hi all,

I am wondering about Resr meaning in datasheet schemas.

I am interested at following Lowest Cost schema:

The datasheet indicate me only the minimum values for Resr:

 

At the end, I need an Resr >= 42mOhm.

The WEBENCH online tool allows only Ceramic capacitors for Cout with an SMD series resistor Resr like in the above scheme.

Is there any reason beacause I cannot use a single Electrolytic capacitor with an internal ESR of 600mOhm instead of the 2 separated components ( ceramic Cout + Resr ) ?

Thanks for your support.

regards,

Lorenzo

  • +1
    TI__Expert 8130 points

    Hello Lorenzo,

    I would not recommend to use an Electrolytic Cap for Cout. In general, low-ESR capacitors are good choices for Cout. They provide excellent energy storage and improve the transient performance.
    Based on the capacitor type, the ripple generated can look very different. The ripple depends on the capacitor impedance and ceramic caps are great in parasitics which helps reduce the ripple amplitude.

    I would recommend to follow as suggested in datasheet and WEBENCH.

    Regards,
    Alejandro