Piezoelectric driving circuit and driving method thereof

A piezoelectric driving circuit generates a first PWM output according to a result of comparison between a ramp signal and a reference sinewave and generates a second PWM according to a result of comparison between the ramp signal and an inverse reference sinewave of the reference sinewave. The switching operation of the first and third switches of the piezoelectric driving circuit are controlled according to the first PWM output and the switching operation of the second and fourth switches of the piezoelectric driving circuit are controlled according to the second PWM output during a first cycle of the reference sinewave and the inverse reference sinewave. The switching operation of the first and third switches are controlled according to the second PWM output and the switching operation of the second and fourth switches are controlled according to the first PWM output during the next second cycle.