Magnetic disk drive

A magnetic disk drive comprising:

• an H bridge circuit including a magnetic head connected between a pair of junction points where transistors are serially connected, a flowing direction of a recording current flowing through said magnetic head being controlled by switching said transistors of said H bridge circuit in accordance with a first recording signal and a second recording signal of a reverse phase to said first recording signal;
• a resistive element provided between said H bridge circuit and ground for controlling a quantity of said recording current;
• a constant voltage supply for generating a given bias voltage;
• and
• an overshoot controller for controlling a magnitude of overshoot of said recording current caused in reversing the flowing direction of said recording current,
• wherein said overshoot controller includes:
• a first capacitive element provided between a first recording signal input terminal and a base or a gate of a first transistor that is one of said transistors of said H bridge circuit for controlling the quantity of said recording current and is turned on in accordance with said first recording signal;
• a second capacitive element provided between a second recording signal input terminal and a base or a gate of a second transistor that is another of said transistors of said H bridge circuit for controlling the quantity of said recording current and is turned on in accordance with said second recording signal;
• a second resistive element for applying said given bias voltage generated by said constant voltage supply to the base or the gate of each of said first and second transistors;
• a third transistor that is connected between said second resistive element and the base or the gate of said first transistor and is turned on in accordance with said first recording signal;
• and
• a fourth transistor that is connected between said second resistive element and the base or the gate of said second transistor and is turned on in accordance with said second recording signal, and
• said first and second capacitive elements share said second resistive element and alternately construct first and second differential pulse generation units by switching said third and fourth transistors.