Monolithic controller for low-power converters with piezoelectric transformer

In this paper a piezoelectric transformer controller circuit is presented. The circuit can be used to implement piezoelectric transformer based dc-dc converters for low-power applications. The controller includes both a transformer driving stage and control circuitry for closed loop operation. The control strategy implemented is adaptive and based on a frequency and duty cycle modulation. The controller was integrated on a silicon chip and tested on a dc-dc converter designed for a high voltage (1 kV) low power (300 mW) application. Experimental results are given.