METHOD OF AND APPARATUS FOR GENERATING INDEX PULSE

摘要

PURPOSE: A method of and an apparatus for generating an index pulse are provided an improved interface between a spindle motor driver IC and an FDD control IC by using positive pulse and negative pulse. CONSTITUTION: A method of generating an index pulse utilizes a magnetic unit mounted at an outer periphery of a rotor of a motor and a hall element for sensing magnetism generated from the magnetic unit and generating a positive signal and a negative signal of antiphase. The method comprises a first step of fluctuating an electric potential of either of the positive signal or negative signal output from the hall element, a second step of performing differential amplification onto a difference between the signal fluctuated in the first step and the other signal, and a third step of detecting a characteristic curve in accordance with a preset hysteresis characteristic from the signal differentially amplified in the second step.