Abstract: A motor driving circuit for driving a direct-current (DC) motor, includes a driving circuit for converting an input voltage into a first and a second output voltages, a Hall sensor for generating a first and a second time sequential control signals according to a working condition of the DC motor, a current sensing unit for detecting a motor current through the DC motor and comparing the motor current to a reference current to generate a comparison result and determine a first transition voltage selector value accordingly, and a control unit coupled to the driving circuit, the current sensing unit and the Hall sensor for controlling a working status of the driving circuit according to the first and the second time sequential control signals and the first transition voltage selector value.

Abstract: The present invention discloses a start-up circuit for a motor driving IC. The activation circuit includes a determination unit, for generating a determination result indicating an operating mode of the motor driving IC according to an external pulse width modulation signal, and an output unit, for outputting an activation signal according to the determination result and a pulse width modulation activation signal. A duty of the pulse width modulation activation signal is greater than a duty of the external pulse width modulation signal.

Abstract: A motor driving circuit for driving a motor includes: a driving-stage circuit, for converting an input voltage into a first output voltage and a second output voltage, and comprising a first transistor, a second transistor, a third transistor and a fourth transistor; an output stage circuit, for converting the first output voltage or the second output voltage into a motor speed signal; and a control unit, coupled to the first, the second, the third and the fourth transistors and the output stage circuit, for generating first, second, third and fourth transistor control signals to control the first, the second, the third and the fourth transistors respectively.

Abstract: A method for adjusting rotational speed of a motor is also disclosed. The method includes determining whether an input voltage of the motor enters into a predetermined voltage range; generating a pulse width modulation signal when the input voltage of the motor enters into the predetermined voltage range; and driving the motor to rotate according to the pulse width modulation signal.

Abstract: The present invention discloses a pulse width modulation driving IC. The pulse width modulation driving IC includes a first pin, for receiving a first signal, a second pin, for receiving a second signal, a comparing unit, for comparing the first signal with a reference voltage, to generate a comparison result indicating a operating mode of the pulse width modulation driving IC, and an output unit, for outputting a pulse width modulation output signal according to the first signal, the second signal and the comparison result.

Abstract: A method for adjusting rotational speed of a motor is also disclosed. The method includes determining whether an input voltage of the motor enters into a predetermined voltage range; generating a pulse width modulation signal when the input voltage of the motor enters into the predetermined voltage range; and driving the motor to rotate according to the pulse width modulation signal.

Abstract: Power control circuit with reducing noise and switching loss includes a first gate driver for driving a first switch, an additional gate driver for driving the first switch, and a managing circuit for controlling the first and the additional gate driver to drive the first switch according to a switching signal and turning off the additional gate driver according to a switching voltage on a first end of the first switch, wherein the first end of the first switch is coupled to a load, second end of the first switch is coupled to an input power source, a third end of the first switch is coupled to the first and the additional gate drivers.

Abstract: A circuit protection method for a motor control circuit includes determining whether the motor control circuit complies with an operating condition when the motor control circuit is in a start mode, a lock mode or a restart mode, and modulating a current outputted from the motor control circuit when the motor control circuit complies with the operating condition.

Abstract: The present invention discloses a motor driving circuit for driving a motor, including an electrostatic discharge diode, having an input port and an output port coupled to a first DC power supply, a pulse width modulation source coupled to the input port of the electrostatic discharge diode to generate a pulse width modulation signal, and a driving module including a voltage detecting module comparing the pulse width modulation signal with a voltage of the output port of the electrostatic discharge diode to generate a voltage comparison result, a lock/restart module generating a shut-down signal according to the voltage comparison result, a control module generating a control signal according to the shut-down signal, and a bridge circuit switching the motor on or off by turning on or turning off an up-bridge circuit and a down-bridge circuit according to the control signal.

Abstract: A rotation speed control circuit for controlling a rotation speed of a fan includes: a rotation speed detector, for generating a rotation speed voltage according to a rotation speed signal corresponding to the rotation speed; a sample and hold element, coupled to the rotation speed detector, for sampling and storing the rotation speed voltage; an error amplifier, coupled to the sample and hold element, for controlling a voltage of a filter capacitor according to the rotation speed voltage and a reference voltage, to adjust an error voltage; and a pulse width modulation signal generator, coupled to the filter capacitor, for generating a pulse width modulation signal according to the error voltage and a triangle wave.

Abstract: An over voltage protection circuit is disclosed. The over voltage protection circuit comprises an input end, coupled to an input power, for receiving an input voltage provided by the input power; and a driving module, coupled between the input end and a ground end, for generating a discharging current when the input voltage is larger than a predefined voltage, to reduce the input voltage to the predefined voltage.

Abstract: The present invention discloses a start-up circuit for a motor driving IC. The activation circuit includes a determination unit, for generating a determination result indicating an operating mode of the motor driving IC according to an external pulse width modulation signal, and an output unit, for outputting an activation signal according to the determination result and a pulse width modulation activation signal. A duty of the pulse width modulation activation signal is greater than a duty of the external pulse width modulation signal.

Abstract: The present invention discloses a pulse width modulation driving IC. The pulse width modulation driving IC includes a first pin, for receiving a first signal, a second pin, for receiving a second signal, a comparing unit, for comparing the first signal with a reference voltage, to generate a comparison result indicating a operating mode of the pulse width modulation driving IC, and an output unit, for outputting a pulse width modulation output signal according to the first signal, the second signal and the comparison result.

Abstract: Power control circuit with reducing noise and switching loss includes a first gate driver for driving a first switch, an additional gate driver for driving the first switch, and a managing circuit for controlling the first and the additional gate driver to drive the first switch according to a switching signal and turning off the additional gate driver according to a switching voltage on a first end of the first switch, wherein the first end of the first switch is coupled to a load, second end of the first switch is coupled to an input power source, a third end of the first switch is coupled to the first and the additional gate drivers.

Abstract: A motor driving method for driving a direct-current (DC) motor, designed for avoiding a reverse current induced by the Back Electromotive Force (BEMF), includes providing a driver circuit for driving the DC motor; comparing a signal level of a terminal of the DC motor and a predetermined voltage value to produce a comparing result; and controlling a specific lower gate switch to avoid the occurrence of a reverse current of the DC motor according to the comparing result.

Abstract: A control method of a current limit of a DC motor includes generating a reference voltage according to a preset current limit value of a DC motor; comparing the reference voltage with the voltage drop of a power control switch which drives the DC motor to generate a compare result; and controlling the power delivered to the DC motor according to the compare result in order to limit the current of the DC motor.

Abstract: A sensorless method for starting a three-phase brushless direct-current motor includes generating a start-up control signal, a start mode selection signal, and a control signal commutation period; switching to a start mode according to the start mode selection signal; implementing a position aligning procedure according to the start-up control signal and the control signal commutation period; detecting a zero crossing point of back electromotive forces during each control signal commutation period; outputting a sensorless mode selection signal while detecting the zero crossing points of the back electromotive forces during consecutive control signal commutation periods; switching to a sensorless mode according to the sensorless mode selection signal; and detecting a zero crossing point of back electromotive forces in the sensorless mode to determine a starting result of the three-phase brushless direct-current motor.

Abstract: A rotation speed control circuit for controlling a rotation speed of a fan includes: a rotation speed detector, for generating a rotation speed voltage according to a rotation speed signal corresponding to the rotation speed; a sample and hold element, coupled to the rotation speed detector, for sampling and storing the rotation speed voltage; an error amplifier, coupled to the sample and hold element, for controlling a voltage of a filter capacitor according to the rotation speed voltage and a reference voltage, to adjust an error voltage; and a pulse width modulation signal generator, coupled to the filter capacitor, for generating a pulse width modulation signal according to the error voltage and a triangle wave.

Abstract: A driving method for a motor includes sensing variation of magnetic pole of a rotator of the motor, to generate a magnetic pole sensing signal, determining dead zone of the motor according to the magnetic pole sensing signal, to generate a determination result, and adjusting voltage outputted to a coil of the rotator according to the determination result.

Abstract: A motor driving circuit for adjusting speed of the motor by changing output voltage is disclosed. One end of the motor is coupled to a variable voltage source. The motor driving circuit includes a motor-driving unit, a control unit and a determining unit. The motor-driving unit includes a first end coupled to another end of the motor, a second end coupled to a ground and a third end, and is utilized for driving the motor. The control unit is utilized for controlling the voltage between the first end and the third end of the motor-driving unit. The determining unit is coupled between the variable voltage source and the control unit, and is utilized for controlling the control unit to adjust the voltage between the first end and the third end of the motor-driving unit according to magnitude of the voltage of the variable voltage source.