| 摘要 |
PURPOSE:To inhibit the rotational unevenness (a jitter component) of a motor. CONSTITUTION:The switching of the output transistors Q1-Q6 of an output section 12 is controlled, and the specified currents of three layers are made to flow successively through coils L1-L3, thus driving a motor. The torque command of the motor is generated by comparing an FG as the signal of the revolution of the motor and the phase of a reference clock by a PLL control section 22. On the other hand, a PWM generating section 50 determines the power-supply side voltage VM of the output transistors Q1-Q6 from the state of the fluctuation of driving voltage to the motor. Since both the PLL control section 22 and a PWM control section are operated by a reference clock from a reference-clock generating section 40, the fine change of motor supply currents resulting from the mutual intervention of signals can be inhibited, thus preventing the rotational unevenness of the motor. |
