Switching circuit

A switching circuit, comprising:

• a drive power supply which includes a positive electrode terminal and a negative electrode terminal, and outputs a predetermined drive voltage;
• a first transistor and a second transistor which are connected in parallel;
• a drive signal source which outputs a drive pulse signal for turning on and off the first transistor and the second transistor;
• and
• a drive circuit, which includes a power supply terminal and a ground terminal, receives supply of electric power from the drive power supply, and outputs, according to the drive pulse signal, a first drive signal for turning on and off the first transistor and a second drive signal for turning on and off the second transistor,
• wherein each of the first transistor and the second transistor includes:
• a drain electrode and a source electrode in which a main current flows when a corresponding one of the first transistor and the second transistor is ON;
• a gate electrode which changes an impedance between the drain electrode and the source electrode according to a corresponding one of the first drive signal and the second drive signal;
• a gate terminal connected to the gate electrode;
• a drain terminal connected to the drain electrode;
• a first source terminal connected to the source electrode for passing the main current between the drain electrode and the source electrode;
• and
• a second source terminal connected to the source electrode for detecting a source voltage and flowing a gate drive current, the second source terminal being provided in addition to the first source terminal,
• the first source terminal is connected to the source electrode at an impedance lower than an impedance of the second source terminal,
• the drain terminal of the first transistor and the drain terminal of the second transistor are connected to each other,
• the first source terminal of the first transistor and the first source terminal of the second transistor are connected to each other,
• the gate terminal of the first transistor receives the first drive signal,
• the gate terminal of the second transistor receives the second drive signal, and
• the second source terminal of the first transistor and the second source terminal of the second transistor are individually and separately connected to a portion of a wiring line which connects the negative electrode terminal of the drive power supply and the ground terminal of the drive circuit.