A semiconductor device has a drive unit outputting a first drive signal to a first electrode and a second drive signal to a second electrode, an instruction signal generation unit generating an instruction signal as a basis of the drive signals and a control unit outputting a first control signal as a basis of the first drive signal and a second control signal as a basis of the second drive signal, based on the instruction signal to control the drive unit. The control unit synchronizes the first control signal with the instruction signal, delays a turning-on timing of the second control signal by a predetermined time relative to the instruction signal and determines a turning-off timing of the second control signal based on a previous pulse width of the instruction signal.