Patent ID: 8598919

Claim:
A signal output circuit for outputting a drive signal to a voltage-controlled switching element, which is connected in series with a load between a power source and a ground, in accordance with a control signal inputted thereto, the signal output circuit comprising: a current generation circuit for generating a current in proportion to a potential difference between a potential at a control terminal of the switching element and either one of a voltage of a controlled power source and a ground potential; a first current mirror circuit for supplying, as a mirror current, a current generated by the current generation circuit, the first current mirror circuit having a current path connected to the control terminal of the switching element; and a control part for controlling an operation of the charging and discharging of a capacitance component, which the switching element has between the control terminal and an output terminal connected to the load, in accordance with a level change of the control signal, wherein the control part includes an amplifier circuit, which has a transistor connected to the current path of the first current mirror circuit, and a switch circuit, which is configured to control an operation of the amplifier circuit in accordance with the level change of the control signal, wherein the switch circuit stops the operation of the amplifier circuit to thereby charge the capacitance component with a charge current supplied from the current mirror circuit, and wherein the switch circuit allows the operation of the amplifier circuit to supply a discharge current for discharging the capacitance component at a same current value as the charge current.