Design procedure for reduced filter size in a buck converter using a 4th-order resonance filter
Ó Mathúna, Cian
Institute of Electrical and Electronics Engineers (IEEE)
This article presents a novel design procedure for 4th order and 4th order resonance (4thRes) output filters, for given buck converter specifications, making components selection a straightforward process. An accurate filter analysis is provided to predict the filter component currents and voltages in both frequency and time domains. Application of the analysis in a design study of a 20 MHz, 5.4 W buck converter shows that the 4thRes filter has the potential to reduce the output passive components for a wide duty cycle range. As compared with a 2nd order filter at V IN = 6.6 V to V OUT = 1.8 V, total inductance, inductor energy, capacitance, and capacitor energy are 58%, 35%, 45%, and 31% lower, respectively. Air-core PCB integrated solenoid inductors are considered for implementation and testing within a prototype converter to show the impact of these filters on the converter performance. The 4thRes filter achieved 3.7% and 3.6% higher full-load efficiency than the 2nd and 4th order filters, respectively, and a better load transient performance.
Buck converter , 4th order resonance filter , PCB inductor , Solenoid inductor
Kandeel, Y., O'Driscoll, S., Ó Mathúna, C. and Duffy, M. (2022) 'Design procedure for reduced filter size in a buck converter using a 4th-order resonance filter', IEEE Transactions on Power Electronics. doi: 10.1109/TPEL.2022.3206050