A piezo ceramic transformer working at a full wave length mode, &lgr;-mode, in accordance with the present invention has a driving region divided into two sections in the center and two generating regions at the end regions of a thin rectangular bar. Two input sections are built into multi-layered structure with multiple internal-electrodes and poled along the thickness direction with polarization in the neighboring layers opposite to each other. Alternating internal electrodes are connected in parallel through two external electrodes in each input section. Polarization in the same layer of two input sections are disposed in the same direction, and two external electrodes of two input sections in the same side of driving region are connected 180 degree out of phase to each other to a driving circuit. Two CCFLs are connected directly to two output electrodes at the end of the piezo ceramic transformer, respectively. Polarization in two output sections is along the length of the piezo ceramic plate, but the respective direction is in opposite way. Alternatively, polarization in the same layer of the two input sections are disposed in opposite direction, and two external electrodes of two input sections in the same side are connected in phase to each other to a driving circuit.