CLASS-D VOLTAGE-SWITCHING INVERTER WITH TAPPED RESONANT INDUCTOR

A steady-state analysis and experimental verification are given for a Class D voltage-switching inverter whose resonant circuit consists of a resonant capacitor in series with a tapped inductor. The analysis of the inverter is carried out in the frequency domain using Fourier series techniques. Design equations describing the steady-state operation are derived. It is found that the DC-to-AC voltage transfer function of the inverter is almost independent of the load variations at a switching frequency higher than the resonant frequency. In addition, the circuit has high efficiency over a wide range of load resistance. A prototype of the inverter was built and tested at an output power of 64 W using IRF730 power MOSFETs. The theoretical and experimental results show excellent agreement.