| 摘要 |
In a PWM-controlled motor driving device, a phase current is prevented from undergoing an abrupt transition at phase current switching points, thereby reducing vibrations and noise of the motor. A PWM control section produces two independent PWM control pulse signals P1 and P2. Two energized phases, which are determined by an energization switching section, are energized with PWM control in parallel according to the PWM control pulse signals P1 and P2. A comparison section compares a current detection signal DS, which indicates the level of the current flowing through a motor coil, with various torque command signals TQ1, TQ2 and TQ3, which are produced by a torque command signal generation section. A masking section masks comparison results CR1 and CR2 as necessary. Thus, an ON period of the PWM control pulse signal P1 and that of the PWM control pulse signal P2 are determined. In this way, phase current switching can be done smoothly with any torque from a low torque to a high torque, thereby preventing an abrupt phase current transition. <IMAGE> |
