Magnetic head driver circuit and magnetic storage device
View Patent ↗A driver circuit drives a write element for magnetic recording, and permits high speed recording while preventing noise from entering an adjacent read element. An H bridge circuit, which causes a write current to flow, in accordance with a write drive signal, in a write coil of the write element, is provided with an overshoot circuit, in which positive and negative power sources are of the same potential. It makes a flyback voltage vertically symmetrical. Further, a feedback circuit is provided which monitors the voltages at both ends of the write coil, and prevents a variation in the common potential of the write coil. Terminal resistors are further provided to prevent the effects of reflection in a transmission line, and to prevent a change in the write waveform.
1. A magnetic head driver circuit for driving a write element performing magnetic recording on a magnetic recording medium, comprising:
a write driver comprising a first pair of switch elements for directing a write current in one direction in a write coil of said write element; and a second pair of switch elements for directing a write current in a reverse direction in said write coil; and
an overshoot circuit, which is connected to a positive power source and a negative power source of the same potential, for adding an overshoot current to said write coil in sync with the operation of said first and second pairs of switch elements, said overshoot current preventing a variation in a common potential of said write coil.
2. The magnetic head driver circuit according to claim 1 , wherein said overshoot circuit comprises:
a third pair of switch elements for directing an overshoot current in said one direction to said write coil, in accordance with a drive signal in sync with a write drive signal of said first pair of switch elements; and
a fourth pair of switch elements for directing an overshoot current in said reverse direction through said write coil, in accordance with a drive signal in sync with a write drive signal of said second pair of switch elements.
3. A magnetic head driver circuit for driving a write element performing magnetic recording on a magnetic recording medium, comprising:
a write driver comprising a first pair of switch elements for directing a write current in one direction in a write coil of said write element; and a second pair of switch elements for directing a write current in a reverse direction in said write coil;
an overshoot circuit, which is connected to a positive power source and a negative power source of the same potential, for adding an overshoot current to said write coil, in sync with the operation of said first and second pairs of switch elements, said overshoot current preventing a variation in the common potential of said write coil; and
a feedback circuit for monitoring the voltages at both ends of said write coil and controlling a supply voltage which is applied to said write driver.
4. A magnetic storage device comprising:
a write element for performing magnetic recording on a magnetic recording medium;
a read element for reading the magnetic recording medium;
a write driver comprising a first pair of switch elements for directing a write current in one direction in a write coil of said write element; and a second pair of switch elements for directing a write current in a reverse direction in said write coil; and
an overshoot circuit, which is connected to a positive power source and a negative power source of the same potential, for adding an overshoot current to said write coil in sync with the operation of said first and second pairs of switch elements, said overshoot current preventing a variation in a common potential of said write coil.
5. The magnetic storage device according to claim 4 , wherein said overshoot circuit comprises:
a third pair of switch elements for directing an overshoot current in said one direction to said write coil, in accordance with a drive signal in sync with a write drive signal of said first pair of switch elements; and
a fourth pair of switch elements for directing an overshoot current in said reverse direction through said write coil, in accordance with a drive signal in sync with a write drive signal of said second pair of switch elements.
6. A magnetic storage device comprising:
a write element for performing magnetic recording on a magnetic recording medium;
a read element for reading the magnetic recording medium;
a write driver comprising a first pair of switch elements for directing a write current in one direction in a write coil of said write element; and a second pair of switch elements for directing a write current in a reverse direction in said write coil;
an overshoot circuit, which is connected to a positive power source and a negative power source of the same potential, for adding an overshoot current to said write coil, in sync with the operation of said first and second pairs of switch elements, said overshoot current preventing a variation in the common potential of said write coil; and
a feedback circuit for monitoring the voltages at both ends of said write coil and controlling a supply voltage which is applied to said write driver.