Design Methodology and Procedure for a Ferromagnetic Planar Coil With Series–Parallel Compensation in DC–DC Converter Applications

This study presents the design, analysis, and implementation of a ferromagnetic planar coil integrated with a series–parallel compensation network and a half-bridge switching circuit for the development of a DC–DC converter. A few studies revealed the design method of the planar coil with the ferrite core and the derivation of equations to calculate the inductance value and the spiral winding turns for the planar coils and provided design examples for verification; therefore, this study designed a ferromagnetic planar coil incorporated with a series–parallel compensation network. Based on the electrical specification of the DC–DC converter, the required inductance value and number of spiral winding turns were calculated. The design was subsequently validated through simulation, measurement, and experiment. This paper presents a comprehensive design description along with the corresponding flowchart, the core dimensions, and assembly configurations of the planar coils, along with the estimated inductance and spiral winding turns for both circular and square geometries. Furthermore, the resonant components of the series–parallel compensation network were determined, and the voltage gain–frequency response of the DC–DC converter was simulated and cross-validated with measurements from the developed prototype.