State-of-the-art piezoelectric transformer technology

To date, piezoelectric transformers (PTs) have been extensively commercialised in step-up applications, such as cold cathode fluorescent lamp backlighting for LCDs. As step-down PT technology matures, PT-based converters are set to replace conventional transformers and power converters in a wide variety of applications that require relatively low power levels, low cost, high efficiency, high power density, small size and weight, low EMI, and high reliability. This paper examines the various types of piezoelectric transformer and provides an overview of the materials technology, converter designs, and control methods involved with their use.