Abstract: A motor driving circuit may include a Hall sensor configured to generate a Hall signal according to the position of a rotor of a motor to be driven; a Hall bias circuit; an analog amplifier configured to amplify the Hall signal; an A/D converter configured to convert the Hall signal into a digital signal; an amplitude control circuit configured to adjust the amplitude of the digital signal; a control signal generating unit configured to generate a control signal to be used to drive the motor; and a driver circuit configured to drive the motor according to the control signal. The components may be monolithically integrated on a single semiconductor substrate. The amplitude control circuit may include an amplitude correction circuit; and a target amplitude judgment circuit configured to adjust the gain of the analog amplifier.

Abstract: First and second A/D converters perform analog/digital conversion of first and second signals of a Hall signal so as to generate third and fourth signals as digital signals. A differential conversion circuit generates a fifth signal as a single-ended signal that corresponds to the difference between the third and fourth signals. An offset correction circuit corrects offset of the fifth signal so as to generate a sixth signal. An amplitude control circuit stabilizes the amplitude of the sixth signal to a predetermined target value, and generates its absolute value, thus generating a seventh signal. A control signal generating unit generates a control signal based upon the seventh signal. A driver circuit drives a motor according to the control signal.

Abstract: The objective of the present invention is to miniaturize a driving circuit of a fan motor. The present invention provides a driving device for driving a fan motor as a three-phase brushless DC motor. An inbuilt Hall component is disposed adjacent to the fan motor and generates a pair of Hall signals corresponding to a rotor position of the fan motor. An internal power source supplies a bias signal to the inbuilt Hall component. A Hall signal processing portion cancels a shift of the pair of Hall signals and amplifies the Hall signal. A driving processing circuit drives the fan motor according to an output signal of the Hall signal processing portion. The driving device is integrated on a semiconductor substrate.

Abstract: First and second A/D converters perform analog/digital conversion of first and second signals of a Hall signal so as to generate third and fourth signals as digital signals. A differential conversion circuit generates a fifth signal as a single-ended signal that corresponds to the difference between the third and fourth signals. An offset correction circuit corrects offset of the fifth signal so as to generate a sixth signal. An amplitude control circuit stabilizes the amplitude of the sixth signal to a predetermined target value, and generates its absolute value, thus generating a seventh signal. A control signal generating unit generates a control signal upon the seventh signal. A driver circuit drives a motor according to the control signal.

Abstract: First and second A/D converters perform analog/digital conversion of first and second signals of a Hall signal so as to generate third and fourth signals as digital signals. A differential conversion circuit generates a fifth signal as a single-ended signal that corresponds to the difference between the third and fourth signals. An offset correction circuit corrects offset of the fifth signal so as to generate a sixth signal. An amplitude control circuit stabilizes the amplitude of the sixth signal to a predetermined target value, and generates its absolute value, thus generating a seventh signal. A control signal generating unit generates a control signal based upon the seventh signal. A driver circuit drives a motor according to the control signal.