• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 62 subscribers
  • Views 86 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.

LM706A0-Q1: Schematic review

Vidit Katlana
Prodigy 85 points
Part Number: LM706A0-Q1


Hello,

We have come up with 2 buck converter design using LM706A0-Q1. Both are 8.4V, one is 8A and other is 5A

8.4V 8A

image.png

8.4V 5A

image.png

Hopefully the screenshot has all the details.

I am also attaching the quickstart excel sheet along with this post.

LM70XX0_8V4_8A_5A.zip 

Please review these and provide your valueble feedback. Please do let us know if we will be heating the IC too much and the output input ripple will be in condition.

Please do let us know other thing you think should be improved or any particular thing we should keep in mind during layout stage

Thanks!

 

  • 0
    TI__Genius 13250 points

    Hi,

    The boot capacitor values should be 47 nF, not 4.7 nF in both the cases. Otherwise the schematics look good to me.

    I don't see anything from the schematic side that should cause heating in the IC. But it would also depend heavily on the layout. Since the currents are high you would need to ensure enough copper area to dissipate the heat. There are layout guidelines given in datasheet section 8.4, which should be followed as closely as possible. If you have any particular questions on those, let me know.

    Regards,

    Niranjan

  • 0 in reply to Niranjan Nair
    Prodigy 85 points

    Hello Niranjan.

    Thank you for pointing out the mistake and the feedback.

    Do you think FPWM and PFM mode make any difference, and other setting which will keep the heating minimum?

    Thanks!

    Vidit

  • 0 in reply to Vidit Katlana
    TI__Genius 13250 points

    Hi Vidit,

    FPWM/PFM would make a difference at light load. The light load efficiency and hence heating would be much better for PFM. But they would function the same at higher loads. So heating-wise, since you would need to account for 5A current anyway it won't make any difference. I don't see much else to be done in the schematic to improve efficiency/heating, it should be accounted for during the layout.

    If you expect the load to be off/disabled for a long time and the efficiency during no load/light load is important then you can go for PFM. But this would make the output ripple, EMI etc. worse. You can choose depending on what is more critical.

    Regards,

    Niranjan