Abstract: A control system includes a position control module, a power control module, and a diagnostic module. The position control module applies a driving current for positioning a rotor of a motor at one of first and second positions. The power control module applies a first voltage to one of first and second phases of the motor to generate a first current after the position control module applies the driving current to position the rotor at the first position. The power control module applies a second voltage to one of the first and second phases to generate a second current after the position control module applies the driving current to position the rotor at the second position. The diagnostic module determines when the rotor is restricted from rotating based on the first and second currents.

Abstract: A spindle/voice coil motor (VCM) driver includes a clock management module that receives a system clock signal and a second clock signal, and that selects one of the system clock signal or the second clock signal as a selected clock signal. A reference generating module generates a reference signal. A ramp generating module receives the selected clock signal and generates a ramp signal. A pulse width modulation (PWM) module receives the reference signal and the ramp signal and outputs a first PWM driver signal based thereon.

Abstract: A disk drive system is set forth that comprises a rotatable storage medium adapted to store data, a spindle motor disposed to rotate the rotatable storage medium, and a spindle motor control system. The spindle motor control system brakes rotation of the spindle motor in response to inductive sensing of the rotation of the spindle motor.

Abstract: A system and method for determining the rotational speed of a motor, such as a three-phase disk drive motor, detects back electromotive force voltage generated during operation of the motor with an automatic pole calibration to minimize or eliminating variations in the wave of a freeze signal. A phase voltage at a winding is compared against a center tap (CT) voltage. Once the phase voltage falls to a specified voltage level, a detect signal is generated. A predetermined time after the detect signal is generated, a freeze signal is generated for freezing at least the circuit associated with the winding.

Abstract: In a method for measuring motor speed and position by detecting the back EMF generated during pole-pair interactions, a separate respective duration of a power phase suppression signal, that is set during back EMF detection, is stored in memory for each respective pole. The separate respective duration values are determined during a calibration phase by iteratively lengthening each respective duration one unit at a time (up to a maximum value) until no part of the respective back EMF signal occurs outside the suppression signal duration, and those values are stored. During operation, the approach of a pole-pair interaction may be determined from the electrical cycle of the power supply, and then the stored duration value is used to control the state of the suppression signal.

Abstract: In a method for measuring motor speed and position by detecting the back EMF generated during pole-pair interactions, a separate respective duration of a power phase suppression signal, that is set during back EMF detection, is stored in memory for each respective pole. The separate respective duration values are determined during a calibration phase by iteratively lengthening each respective duration one unit at a time (up to a maximum value) until no part of the respective back EMF signal occurs outside the suppression signal duration, and those values are stored. During operation, the approach of a pole-pair interaction may be determined from the electrical cycle of the power supply, and then the stored duration value is used to control the state of the suppression signal.