Motor driving circuit and motor driving system

摘要

The characteristic is defined by a characteristic line that connects a lowest point at which the duty of the PWM signal is a minimum value and the rotation command signal is a minimum rotation command signal, and a highest point at which the duty of the PWM signal is a maximum value and the rotation command signal is a maximum rotation command signal. The duty calculating circuit updates the characteristic so that the characteristic line passes through a first control point at which the duty of the PWM signal is a value set based on the first setting signal and the rotation command signal is a first rotation command signal between the minimum rotation command signal and the maximum rotation command signal.

主权项

1. A motor driving circuit that controls driving of a motor with a PWM signal so that the motor rotates at a number of revolutions specified by a rotation command signal, comprising:
a first port to which the rotation command signal that defines the number of revolutions of the motor is input; a first measuring circuit that measures the rotation command signal; a second port to which a first setting signal is input; a second measuring circuit that measures the first setting signal; a duty calculating circuit that calculates a duty corresponding to the measured rotation command signal based on a characteristic that defines a relationship between the rotation command signal and a duty of the PWM signal, and outputs a duty information signal corresponding to the calculated duty; a motor driving waveform controlling circuit that generates and outputs the PWM signal having the calculated duty based on the duty information signal; a third port to which a second setting signal is input; and a third measuring circuit that measures the second setting signal, wherein the characteristic is defined by a characteristic line that connects a lowest point at which the duty of the PWM signal is a minimum value and the rotation command signal is a minimum rotation command signal, and a highest point at which the duty of the PWM signal is a maximum value and the rotation command signal is a maximum rotation command signal, and the duty calculating circuit updates the characteristic so that the characteristic line passes through a first control point at which the duty of the PWM signal is a value set based on the first setting signal and the rotation command signal is a first rotation command signal between the minimum rotation command signal and the maximum rotation command signal, and wherein the duty calculating circuit updates the characteristic so that the characteristic line passes through the first control point and a second control point at which the duty of the PWM signal is a value set based on the second setting signal and the rotation command signal is a second rotation command signal between the minimum rotation command signal and the maximum rotation command signal.