In recent years, piezoelectric materials have particularly found advantageous field of application in electrical energy’s conversion. Especially, the piezoelectric transformers are becoming more and more usable in electrical devices owing to several advantages such as small size, high efficiency, no electromagnetic noise, and non-flammability. The purpose of this study was to investigate a transformer design that allows having multi-functionality with different efficiency and wider range of voltage gain at resonance frequency. The piezoelectric transformer construction utilizes radial mode both at the input and output port and has the unidirectional polarization in the ceramics. An electromechanical equivalent circuit model based on Mason’s equivalent circuit was developed so as to describe the characteristics of the piezoelectric transformer. Excellent matching was found between the simulation data and experimental results. Finally, the results of this study will allow to deterministically designing multifunction piezoelectric transformers with specified performance.