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UCC28180: output voltage ripple

K.Yaita
Guru 29720 points
Part Number: UCC28180

Hi Team,

My customer designed his board with UCC28180 in accordance with "UCC28180 Design Calculator".
He said output voltage ripple is larger than expected when full load (1500W) so wants to improve.

Regarding UCC28180EVM, Figure 13 also shows 10V Vpp on the output.
http://www.ti.com/lit/ug/sluuat3b/sluuat3b.pdf
Is there any way to improve the voltage ripple?

Best Regards,
Yaita

  • 0
    TI__Expert 6080 points
    Hello Yaita,

    The output voltage ripple depends on the output cap, Fline and the Pout only. Please share this information from the customer design. The ESR of the output cap can also significantly contributes to the output ripple. Normally, to increasing the value of Cout or choosing a cap with lower ESR will make the ripple better.

    Regards,
    Sonal
  • 0
    TI__Mastermind 34465 points

    Hello Yaita-san,

    The output ripple is set by the value of the output capacitance.
    In the UCC28180 calculate you can see that increasing the output capacitance will decrease output ripple peak to peak.
    The calculator is actually set up to ask the use to specify a holdup time and a holdup voltage so it is not immediately clear about the ripple.
    You can select the output capacitance and the calculator will show you the resulting ripple on Row 134

    Regards

    John