CIRCUIT FOR SENSING DRIVING STATE OF SPINDLE MOTOR IN DISC DRIVING SYSTEM

摘要

PURPOSE: A circuit for sensing a driving state of a spindle motor in a disc driving system is provided to precisely sense the driving state of the spindle, thereby preventing inaccurate data access or the damage of a head or a disc. CONSTITUTION: A circuit for sensing a driving state of a spindle motor in a disc driving system includes a spindle motor(10) having a state and a rotor mounted to the stator, and a driving state sensing element(22) for sensing the driving state of the spindle motor. The spindle motor detects the magnetic flux provided by a plurality of magnetic polarities of the rotor to realize the relative positions of the stator and the rotor, thereby generating a reference phase signal and three phase signals. The driving state sensing circuit detects a phase difference between at least two of the three phase signals for generating a sensing signal which shows periodic pulses in response to the periodical phase difference between the two phase signals when the spindle motor operates normally.