Radio frequency dc-dc converters : device characterization, topology evaluation, and design

Abstract

High frequency power conversion is attractive for the opportunities it affords for improved performance. Dc-dc converters operating at high frequencies use smaller-valued energy storage elements, which tend to be physically smaller and lower-cost, and this can result in improved transient performance while retaining high efficiency. One way to achieve high switching frequencies is by using resonant inverter and rectifier topologies and regulating voltage via on-off control. This scheme requires a great deal of investigation of design practices appropriate to high frequency power conversion. The design issues were investigated for a 200 W 160-200 V input 33 V output converter. A comparison of resonant inverter topologies for the power stage was made. Appropriate devices were sought, compared, and characterized. A high frequency gate drive scheme for a large vertical MOSFET was developed. Several prototypes were built and these are also presented.