Patent ID: 7859197

Claim:
An inverter, comprising: a transformer; a first high-side transistor one end of which is connected to an input terminal where an input voltage is applied and the other end of which is connected to a first terminal of a primary coil of said transformer; a first low-side transistor one end of which is connected to a potential fixed terminal where a potential is fixed and the other end of which is connected to the first terminal of the primary coil; a second high-side transistor one end of which is connected to the input terminal and the other end of which is connected to a second terminal of the primary coil; a second low-side transistor one end of which is connected to the potential fixed terminal and the other end of which is connected to the second terminal of the primary coil; a current-voltage converter which converts current through a secondary coil of said transformer into voltage so as to be outputted as a detection voltage; a triangular wave signal generator which generates a triangular wave signal; an error amplifier which outputs an error voltage corresponding to error between the detection voltage and a predetermined reference voltage; and a logic control unit which controls on and off of said first and said second high-side transistor and said first and said second low-side transistor, based on the error voltage outputted from said error amplifier and the triangular wave signal generated by said triangular wave signal generator, wherein said logic control unit turns on said first high-side transistor and said second low-side transistor in a first period during which the triangular wave signal starts from a bottom edge thereof until it reaches the error voltage, then said logic control circuit turns on said first high-side transistor in a second period until the triangular wave signal reaches a peak edge, then said logic control circuit turns on said second high-side transistor in a third period until the triangular wave signal reaches a bottom edge, then said logic control circuit turns on said first low-side transistor and said second high-side transistor in a fourth period until the triangular wave signal reaches again the error voltage, then said logic control circuit turns on said second high-side transistor in a fifth period until the triangular wave signal reaches again a peak edge, and then said logic control circuit turns on said first high-side transistor in a sixth period until the triangular wave signal reaches again a bottom edge.