ZHCSBB1D July 2013 – March 2018 UCC28740
Determine the minimum voltage on the input bulk capacitance, CB1 and CB2 total, in order to determine the maximum Np-to-Ns turns-ratio of the transformer. The input power of the converter based on target full-load efficiency, the minimum input RMS voltage, and the minimum AC input frequency determine the input capacitance requirement.
Maximum input power is determined based on IOCC, VOCV, VCBC (if used), and the full-load conversion-efficiency target.
Equation 11 provides an accurate solution for the total input capacitance based on a target minimum bulk-capacitor voltage. Alternatively, to target a given input capacitance value, iterate the minimum capacitor voltage to achieve the target capacitance value.