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BQ25792: Board design review

Nir Alon
Intellectual 640 points
Part Number: BQ25792

Hi,

looking at the recommended PCB design, I'm not sure about the via count for connecting the inductor with SW1 & SW2, only 4 via...just don't seems right to me.

I plan to design a prototype PCB, and increase the via count from 4 to 10:

TI recommendation:

 

My design looks something like this:

The only thing I'm not so sure about is the GND connection at the IC top part. It is more narrow and far from the IC because of the 4 via supplement.

I do believe that 10 vias would be better than 4 regarding power losses and parasitic induction reduction.

Any thoughts? is this an over kill?

I would appreciate any comments.

Thanks

Nir  

  • 0
    TI__Mastermind 32196 points

    Hello Nir,

    Please allow me time to review this question. I will provide an update after I gather more information.

    Best Regards,

    Christian.

  • +1 in reply to Christian Moyer
    TI__Mastermind 32196 points

    Hello Nir,

    Nir Alon said:
    The only thing I'm not so sure about is the GND connection at the IC top part. It is more narrow and far from the IC because of the 4 via supplement.

    Yes, I would recommend making the GND connection wider and closer to the IC.

    Nir Alon said:

    I do believe that 10 vias would be better than 4 regarding power losses and parasitic induction reduction.

    Any thoughts? is this an over kill?

    I don't see any obvious issues using 10 vias, but 4 vias should be sufficient.

    .

    Best Regards,

    Christian.

  • 0 in reply to Christian Moyer
    Intellectual 640 points

    Hi Christian,

    I agree about the GND connection. It's better to have a smaller current loop at PMID & VSYS - so I'll remove the additional 4 vias for SW1 and SW2

    As you can see, I managed to squeeze 6 via for SW1 and SW2 beneath the IC, so between 4 to 10 vias, 6 would still be better than 4 with no other compromises.

    Thanks for your review

    Nir