Piezoelectric transformer-based DC/DC converter with improved burst-mode control

This paper proposed a new control strategy of piezoelectric transformer based DC-DC converter in burst-mode operation. Burst-mode control is adopted for achieving output voltage regulation and for enabling the converter to operate at constant switching frequency as well as to keep a good efficiency at light load conditions. However, in practice, the piezoelectric transformer (PT) cannot stop instantly to vibrate due to its high quality factor. The delay in the output voltage change, resulting from this behavior influences the accuracy of the regulation. This paper proposes a control strategy to make the piezoelectric transformer can stop more quickly so as to enhance the accuracy of burst-mode control. The proposed method only modifies the control signal of the burst-mode driving circuit.