Patent ID: 7969429

Claim:
A control circuit, said control circuit generating high and low side output signals under control signals received from the outside and sending the output signals to an output circuit, said control circuit comprising: a high side power supply terminal maintained at a potential equal to or above a predetermined lower limit; a floating power supply terminal maintained at a potential equal to a constant voltage lower than the potential of said high side power supply terminal; a low side power supply terminal maintained at a constant potential; a low potential power supply terminal maintained at a potential equal to a constant voltage lower than the potential of said low side power supply terminal; an input circuit generating high and low side control signals based on said control signals; a level shift circuit including a resistance element with a first terminal connected to said high side power supply terminal, and a level shift transistor having an output section, said level shift transistor being connected between a second terminal of said resistance element and said low potential power supply terminal and changing the potential of the second terminal of said resistance element under said high side control signal; a high side circuit including an input terminal connected to the second terminal of said resistance element and converting a potential change of said input terminal into said high side output signal, by using the potential difference between said high side and floating power supply terminals; a low side circuit converting said low side control signal into said low side output signal, by using the potential difference between said low side and low potential power supply terminals; and a bipolar transistor circuit including a collector connected to said high side power supply terminal, an emitter connected to said output section of said level shift transistor, and a base connected to said floating power supply terminal.