Motor control circuit, motor drive control device, and motor unit

A motor control circuit comprising:

• a speed command analyzing unit measuring a duty cycle of an input speed command signal indicating a target rotational speed of a motor to be driven;
• a storage unit storing parameter information for defining a speed curve indicating a relationship between the duty cycle of the speed command signal and the target rotational speed;
• a target rotational speed determining unit determining the target rotational speed based on the parameter information stored in the storage unit and a result of measurement of the duty cycle of the speed command signal by the speed command analyzing unit;
• and
• a drive control signal generating unit generating a drive control signal for controlling driving of the motor based on the target rotational speed determined by the target rotational speed determining unit, wherein
• the parameter information includes resolution information indicating a resolution of the duty cycle of the speed command signal and rotational speed information indicating a rotational speed at an inflection point on the speed curve, and
• the target rotational speed determining unit sets the inflection point for each duty cycle obtained by equally dividing a possible duty cycle range assumed by the speed command signal based on the resolution information, calculates a rotational speed corresponding to the duty cycle of the speed command signal measured by the speed command analyzing unit based on the set inflection point and the rotational speed information, and determines the calculated rotational speed as the target rotational speed.