Gate driver circuit of power transistor, and motor driver circuit

A gate driver circuit for driving a power transistor, comprising:

• a gate line configured to be connected to a gate of the power transistor;
• a source line configured to be connected to a source of the power transistor;
• a first current source configured to source a current to the gate line;
• and
• a second current source configured to sink a current from the gate line,
• wherein the first current source includes:
• a first reference impedance element having one end connected to a power supply line;
• a plurality of first transistor elements installed in parallel between the other end of the first reference impedance element and the gate line;
• a first drive transistor installed between the power supply line and the gate line and being of the same type as the first transistor elements;
• and
• a first error amplifier having an output connected to the gate of the first drive transistor, one input connected to the other end of the first reference impedance element, and the other input to which a first reference voltage is input,
• wherein the first current source is configured to be switched between a state, in which a gate of at least one of the plurality of first transistor elements is connected to the output of the first error amplifier, and an OFF state.

A gate driver circuit for driving a power transistor, comprising:

• a gate line configured to be connected to a gate of the power transistor;
• a source line configured to be connected to a source of the power transistor;
• a first current source configured to source a current to the gate line;
• and
• a second current source configured to sink a current from the gate line,
• wherein the first current source includes:
• a first reference impedance element having one end connected to a power supply line;
• a first reference transistor installed between the other end of the first reference impedance element and the gate line;
• a first drive transistor installed between the power supply line and the gate line and being of the same type as the first reference transistor;
• and
• a first error amplifier having an output connected to a gate of each of the first reference transistor and the first drive transistor, one input connected to the other end of the first reference impedance element, and the other input to which a first reference voltage is input,
• wherein a size of at least one of the first reference transistor and the first drive transistor is variable.