220 V mains 500 kHz class-E converter using a BIMOS

Abstract

Class-E converters enable high-efficiency switching at high switching frequencies and thus fulfil the fundamental preconditions for miniaturisation. This, however, must be paid for with a relatively high voltage stress across the switch causing problems when the converter is operated from the mains. A 500 kHz 21 W electronic lamp ballast for 220 V mains is presented. A cascoded BIMOS incorporating a TV deflection transistor combines rapid switching with the required excessive voltage capability for mains drive. An excellent efficiency of 93% could be achieved.