Abstract: A power converter having a multi-stage high-side driving mechanism is provided. A control circuit outputs a first high-side control signal. A high-side driving circuit, according to the first high-side control signal and a first input voltage signal, outputs a first stage high-side driving signal to a control terminal of a high-side switch. As a result, a voltage of the control terminal of the high-side switch is pulled up to a first stage voltage from zero. Then, the control circuit outputs a second high-side control signal. A charge pump outputs a charging signal. The high-side driving circuit, according to the second high-side control signal and the charging signal, outputs a second stage high-side driving signal to the control terminal of the high-side switch. As a result, the voltage of the control terminal of the high-side switch is pulled up from the first stage voltage to a target voltage.

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.

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.