Patent ID: 6710569
Filing Date: 2004-03-23
Classification: H02P

Abstract:
A motor driving device for driving a motor by energizing motor coils with PWM control, the motor driving device comprising:an energization switching section for determining a first energized phase and a second energized phase to be PWM-controlled, the determination being made at a predetermined cycle; a torque command signal generation section that receives an original torque command signal for producing a first torque command signal and a second torque command signal each having an amplitude according to the original torque command signal, and also producing a third torque command signal, which is obtained by synthesizing the first and second torque command signals together; a comparison section that receives the first to third torque command signals and a current detection signal, which is obtained by detecting a current being supplied to the motor, for comparing the current detection signal with the first to third torque command signals to output a first comparison result, a second comparison result, and a third comparison result, respectively; an oscillation section for producing a first set pulse signal and a second set pulse signal; a PWM control section that receives the first and second set pulse signals and the first and second comparison results for producing a first PWM control signal that is turned ON according to the first set pulse signal and turned OFF according to the first comparison result, and also producing a second PWM control signal that is turned ON according to the second set pulse signal and turned OFF according to the second comparison result; and a masking section that receives the first and second PWM control signals and the first to third comparison results for selectively masking or not masking the first and second comparison results according to the first and second PWM control signals and the third comparison result, wherein: the masking section receives the first and second set pulse signals so as to mask the first comparison result according to the first set pulse signal and mask the second comparison result according to the second set pulse signal; and the motor driving device energizes the first and second energized phases with PWM control in parallel according respectively to the first and second PWM control signals.