2 MHZ POWER CONVERTER WITH PIEZOELECTRIC CERAMIC TRANSFORMER

A power converter with a new piezoelectric transformer is presented. T he piezoelectric transformer, made of lead titanate solid solution cer amic, is operated with a thickness extensional vibration mode. This tr ansformer can operate at high frequency, over several megahertz, with about 90% high efficiency. The resonant frequency for the transformer is 2 MHz. The power converter with the transformer applies the theory for a class-E switching converter using an electromagnetic transformer . Maximum output power was obtained when the switching frequency was s lightly higher than the resonant frequency. 4.4W output power was succ essfully obtained with 52% efficiency at 2.1 MHz switching frequency.