Abstract: The present invention relates to a fan motor driving circuit, a driving method, and a cooling device and an electronic machine using the same. The present invention provides a motor driving circuit capable of suppressing strain on coil current and/or reducing noise. A control circuit a control circuit switches an output phase of an H-bridge circuit based on a Hall signal, and in a soft switching duration (Tss) that starts before and ends after the output-phase switching, slowly varies a duty ratio (DUTY1) of an output voltage (VOUT1) of one leg of the H-bridge circuit over time, and meanwhile, varies a duty ratio (DUTY2) of an output voltage (VOUT2) of another leg of the H-bridge circuit in an opposite direction with respect to the duty ratio (DUTY1) of the output voltage (VOUT1) of the one leg.

Abstract: The present invention relates to a fan motor driving circuit, a driving method, and a cooling device and an electronic machine using the same. The present invention provides a motor driving circuit capable of suppressing strain on coil current and/or reducing noise. A control circuit a control circuit switches an output phase of an H-bridge circuit based on a Hall signal, and in a soft switching duration (Tss) that starts before and ends after the output-phase switching, slowly varies a duty ratio (DUTY1) of an output voltage (VOUT1) of one leg of the H-bridge circuit over time, and meanwhile, varies a duty ratio (DUTY2) of an output voltage (VOUT2) of another leg of the H-bridge circuit in an opposite direction with respect to the duty ratio (DUTY1) of the output voltage (VOUT1) of the one leg.

Abstract: A driving circuit of an electric motor includes: a PWM input pin for externally receiving an input pulse modulation signal with an input duty cycle; a duty cycle to digital converter for receiving and converting the input pulse modulation signal into a first digital value; a slope setting pin for receiving information indicative of a slope of an output duty cycle corresponding to the input duty cycle; a slope acquisition unit for acquiring a second digital value corresponding to the information indicative of the slope; a duty cycle computation unit for generating a linearly increased duty cycle instruction value corresponding to the first digital value by referring to the slope; a digital pulse width modulator for generating a controlling pulse having the output duty cycle corresponding to the duty cycle instruction value; and an output circuit for driving the electric fan motor in accordance with the controlling pulse.

Abstract: A TH terminal receives an analog control voltage VTH which indicates a rotational speed. With a first platform, a capacitor and a discharging resistor are connected in parallel between an OSC terminal and the ground. A charging resistor and a first switch are arranged in series between the OSC terminal and a reference voltage line via which a stabilized voltage is supplied. When an oscillator voltage VOSC that occurs at the OSC terminal reaches an upper-side threshold VH, a switching circuit turns off the first switch. When the oscillator voltage VOSC falls to a lower-side threshold value VL, the switching circuit turns on the first switch. The oscillator voltage VOSC is compared with the voltage at the TH terminal, so as to generate a pulse-modulated control pulse S3.

Abstract: A circuit for driving a fan motor includes: a control input interface circuit configured to generate a first digital value indicating an input duty ratio; a duty calculation unit configured to generate a duty command value linearly increasing with a slope with respect to the first digital value; a digital pulse width modulator configured to generate a control pulse having an output duty ratio corresponding to the duty command value; an output circuit configured to drive a fan motor based on the control pulse; a lock protection circuit configured to switch between an enable state and a disable state and to stop supply of power to the fan motor when lock of the fan motor is detected in the enable state; and a torque-off determination unit configured to switch the lock protection circuit to the disable state in a torque-off state.

Abstract: The present invention inhibits the voltage jump of a source voltage or an output voltage by an approach which is different from a conventional one. A logic circuit allows an H bridge circuit to be shifted among a plurality of states in a specific sequence. A compulsory regenerating circuit is configured to be switched between an enabled state and a disabled state; while being in the enabled state, the current that flows in from a ground line via the H bridge circuit and a motor coil to a power line back-flows to the ground line.

Abstract: A TH terminal receives an analog control voltage VTH which indicates a rotational speed. With a first platform, a capacitor and a discharging resistor are connected in parallel between an OSC terminal and the ground. A charging resistor and a first switch are arranged in series between the OSC terminal and a reference voltage line via which a stabilized voltage is supplied. When an oscillator voltage VOSC that occurs at the OSC terminal reaches an upper-side threshold VH, a switching circuit turns off the first switch. When the oscillator voltage VOSC falls to a lower-side threshold value VL, the switching circuit turns on the first switch. The oscillator voltage VOSC is compared with the voltage at the TH terminal, so as to generate a pulse-modulated control pulse S3.

Abstract: A motor driving apparatus comprises an H bridge circuit having outputs coupled with a motor coil of a single-phase motor, a hall comparator configured to generate a hall detection signal indicating a position of a rotor of the motor, an electric angle generator configured to generate a pulse signal indicating that the motor rotates by a predetermined electric angle, a current monitoring circuit configured to asserts a zero current detection signal upon detecting a reversed direction of a coil current; a transition trigger circuit configured to assert a transition pulse when a count value of the first counter matches an lead angle set value; a logic circuit configured to transition the H bridge circuit according to a predetermined sequence of states; and a lead angle controller configured to adjust the lead angle set value based on a timing of assertion of the zero current detection signal.

Abstract: A motor driving apparatus comprises an H bridge circuit having outputs coupled with a motor coil of a single-phase motor, a hall comparator configured to generate a hall detection signal indicating a position of a rotor of the motor, an electric angle generator configured to generate a pulse signal indicating that the motor rotates by a predetermined electric angle, a current monitoring circuit configured to asserts a zero current detection signal upon detecting a reversed direction of a coil current; a transition trigger circuit configured to assert a transition pulse when a count value of the first counter matches an lead angle set value; a logic circuit configured to transition the H bridge circuit according to a predetermined sequence of states; and a lead angle controller configured to adjust the lead angle set value based on a timing of assertion of the zero current detection signal.

Abstract: The present invention inhibits the voltage jump of a source voltage or an output voltage by an approach which is different from a conventional one. A logic circuit allows an H bridge circuit to be shifted among a plurality of states in a specific sequence. A compulsory regenerating circuit is configured to be switched between an enabled state and a disabled state; while being in the enabled state, the current that flows in from a ground line via the H bridge circuit and a motor coil to a power line back-flows to the ground line.

Abstract: A circuit for driving a fan motor includes: a control input interface circuit configured to generate a first digital value indicating an input duty ratio; a duty calculation unit configured to generate a duty command value linearly increasing with a slope with respect to the first digital value; a digital pulse width modulator configured to generate a control pulse having an output duty ratio corresponding to the duty command value; an output circuit configured to drive a fan motor based on the control pulse; a lock protection circuit configured to switch between an enable state and a disable state and to stop supply of power to the fan motor when lock of the fan motor is detected in the enable state; and a torque-off determination unit configured to switch the lock protection circuit to the disable state in a torque-off state.

Abstract: A driving circuit of an electric motor includes: a PWM input pin for externally receiving an input pulse modulation signal with an input duty cycle; a duty cycle to digital converter for receiving and converting the input pulse modulation signal into a first digital value; a slope setting pin for receiving information indicative of a slope of an output duty cycle corresponding to the input duty cycle; a slope acquisition unit for acquiring a second digital value corresponding to the information indicative of the slope; a duty cycle computation unit for generating a linearly increased duty cycle instruction value corresponding to the first digital value by referring to the slope; a digital pulse width modulator for generating a controlling pulse having the output duty cycle corresponding to the duty cycle instruction value; and an output circuit for driving the electric fan motor in accordance with the controlling pulse.

Abstract: A fan motor driving device driven based on a pair of out-of-phase Hall signals may include a first driving portion, configured to (i) amplify a difference of the pair of the Hall signals with a first polarity and generate a first control signal, and (ii) switch between a driving status and a regeneration status; a second driving portion, configured to (i) amplify the difference of the pair of the Hall signals with a second polarity, and generate a second control signal, and (ii) switch between a driving status and a regeneration status; and a regeneration controller, controlling statuses of the first driving portion and the second driving portion, respectively.

Abstract: A motor driving circuit receives a control pulse signal pulse-width modulated according to a target rotational speed, and drives a fan motor. A start pulse signal generating unit generates a start pulse signal having a predetermined duty ratio. A driving unit drives the fan motor by pulse width modulation according to the driving pulse signal received from a control unit. When the duty ratio of the control pulse signal is switched from zero to a nonzero value when the fan motor is in the stopped state, the control unit commences the driving operation for the fan motor. The control unit outputs, as the driving pulse signal, the start pulse signal, in a predetermined start period Ts from the commencement of the driving operation. After the start period elapses, the control unit outputs the control pulse signal as the driving pulse signal.

Abstract: A cooling system is provided with a motor drive device, a fan motor, and a Hall element. The motor drive device includes a lock protection circuit and a lock controller. When a control signal instructing rotation of the fan motor that is to be driven instructs stoppage of the motor for a predetermined time-period or longer, the lock controller has the lock protection circuit inactive. At an occasion when the control signal has continued to instruct stoppage of the fan motor for a first time-period or longer, a standby controller starts time measurement, and after a further predetermined second time-period has elapsed, makes at least a part of the motor drive device transition to a standby mode.

Abstract: In the motor drive apparatus, a Hall element outputs a first sinusoidal signal and a second sinusoidal signal, of mutually opposite phases, in accordance with rotor position. A hysteresis comparator compares the first sinusoidal signal and the second sinusoidal signal outputted from the Hall element, and outputs a rectangular wave signal. A pulse width modulation signal generation circuit detects timing at which phase switches, based on the first sinusoidal signal and the second sinusoidal signal outputted from the Hall element, and outputs a pulse width modulation signal in which duty ratio gradually changes, in a predetermined time-period in which the phase switches. A drive circuit combines the rectangular wave signal and the pulse width modulation signal by a logical operation, and drives the fan motor.

Abstract: In the motor drive apparatus, a Hall element outputs a first sinusoidal signal and a second sinusoidal signal, of mutually opposite phases, in accordance with rotor position. A hysteresis comparator compares the first sinusoidal signal and the second sinusoidal signal outputted from the Hall element, and outputs a rectangular wave signal. A pulse width modulation signal generation circuit detects timing at which phase switches, based on the first sinusoidal signal and the second sinusoidal signal outputted from the Hall element, and outputs a pulse width modulation signal in which duty ratio gradually changes, in a predetermined time-period in which the phase switches. A drive circuit combines the rectangular wave signal and the pulse width modulation signal by a logical operation, and drives the fan motor.

Abstract: A cooling system is provided with a motor drive device, a fan motor, and a Hall element. The motor drive device includes a lock protection circuit and a lock controller. When a control signal instructing rotation of the fan motor that is to be driven instructs stoppage of the motor for a predetermined time-period or longer, the lock controller has the lock protection circuit inactive. At an occasion when the control signal has continued to instruct stoppage of the fan motor for a first time-period or longer, a standby controller starts time measurement, and after a further predetermined second time-period has elapsed, makes at least a part of the motor drive device transition to a standby mode.

Abstract: In the motor drive apparatus, a Hall element outputs a first sinusoidal signal and a second sinusoidal signal, of mutually opposite phases, in accordance with rotor position. A hysteresis comparator compares the first sinusoidal signal and the second sinusoidal signal outputted from the Hall element, and outputs a rectangular wave signal. A pulse width modulation signal generation circuit detects timing at which phase switches, based on the first sinusoidal signal and the second sinusoidal signal outputted from the Hall element, and outputs a pulse width modulation signal in which duty ratio gradually changes, in a predetermined time-period in which the phase switches. A drive circuit combines the rectangular wave signal and the pulse width modulation signal by a logical operation, and drives the fan motor.

Abstract: A cooling system is provided with a motor drive device, a fan motor, and a Hall element. The motor drive device includes a lock protection circuit and a lock controller. When a control signal instructing rotation of the fan motor that is to be driven instructs stoppage of the motor for a predetermined time-period or longer, the lock controller has the lock protection circuit inactive. At an occasion when the control signal has continued to instruct stoppage of the fan motor for a first time-period or longer, a standby controller starts time measurement, and after a further predetermined second time-period has elapsed, makes at least a part of the motor drive device transition to a standby mode.