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UCC28064A: UCC28064A

Part Number: UCC28064A
Other Parts Discussed in Thread: PMP30763

Hi Support, 

Designing power supply for Avionics using PMP30763 as a guide.  As with PMP30763 the supply is required to meet DO160 Harmonic Limits.   Compared to PMP30763 my supply has higher PFC voltage at 420V and a lower output power of 320 watts.  

What equations, tools, simulations can I use to insure my design is capable of meeting the DO160 Harmonic Limits.  

Regards, 

Stuart

  • Hi Stuart,

    When designing PFC for avionics, the most important thing is to minimize the crossover distortion (which is the lack, or plateau, of current drawn from the AC mains, during zero crossing).  This can be done by minimizing the capacitance placed just after the bridge (because it adds non-linearity to the circuit).

    Referring to page 1 of PMP30763 Rev D, it is possible to minimize the crossover distortion by minimizing the total capacitance (C4 + C5 + C61); some of these capacitors can be moved in parallel to C10 and C9, in case they are needed.

    For the rest of distortion (displacement factor and the part due to the output ripple voltage on C1A,B,C), it is sufficient to have enough capacitance to avoid high ripple (also explained in SLUP093 on page 3) and again minimize the total capacitance C9 + C10 + C4 + C5 + C61.

    I don't have a simulation model but I hope the information I provided helps.

    Regards,

    Ray


    Optimizing High PFC slup093.pdfPMP30763 Rev_D Project.pdf