Abstract: An overvoltage protecting system and method of a motor pre-driver are provided. An overvoltage protecting circuit compares a first reference voltage with a common voltage inputted to a single phase motor to output a first comparison signal. When a controller circuit determines that the common voltage is higher than the first reference voltage according to the first comparison signal, the controller circuit turns off a first high-side switch and a second high-side switch, and turns on the first low-side switch and the second low-side switch, during a phase time of a phase transition signal of the single phase motor. After the phase time ends, the controller circuit alternately turns on the first low-side switch and the second low-side switch according to a level of the phase transition signal.

Abstract: A brake control system of a motor is provided. When a control circuit intends to brake the motor, the control circuit controls a driver circuit to turn off a first high-side switch and a second high-side switch, and to fully turn on the first low-side switch and the second low-side switch, for a period of time. Then, the control circuit controls the driver circuit to turn off one of the first low-side switch and the second low-side switch, and to continually turn on the other one of the first low-side switch and the second low-side switch, for a period of time. Then, the control circuit controls the driver circuit to turn off the other one of the first low-side switch and the second low-side switch, and to turn on the one of the first low-side switch and the second low-side switch, for a period of time.

Abstract: A brake control system of a motor is provided. When a control circuit intends to brake the motor, the control circuit controls a driver circuit to turn off a first high-side switch and a second high-side switch, and to fully turn on the first low-side switch and the second low-side switch, for a period of time. Then, the control circuit controls the driver circuit to turn off one of the first low-side switch and the second low-side switch, and to continually turn on the other one of the first low-side switch and the second low-side switch, for a period of time. Then, the control circuit controls the driver circuit to turn off the other one of the first low-side switch and the second low-side switch, and to turn on the one of the first low-side switch and the second low-side switch, for a period of time.

Abstract: A current limit protecting system and method of a motor pre-driver are provided. A current limiting circuit detects a current of a resistor that is connected to a motor, and then compares the current of the resistor with a current threshold to output a current comparing signal. When a controller circuit determines that the current of the resistor is larger than the current threshold according to the current comparing signal, and a working period of a first signal of a first node or a working period of a second signal of a second node of the motor reaches a preset value, a first high-side switch and a second high-side switch are turned off, and a first low-side switch and a second low-side switch are alternately turned on. As a result, a temperature of the motor generally reduces.

Abstract: A current limit protecting system and method of a motor pre-driver are provided. A current limiting circuit detects a current of a resistor that is connected to a motor, and then compares the current of the resistor with a current threshold to output a current comparing signal. When a controller circuit determines that the current of the resistor is larger than the current threshold according to the current comparing signal, and a working period of a first signal of a first node or a working period of a second signal of a second node of the motor reaches a preset value, a first high-side switch and a second high-side switch are turned off, and a first low-side switch and a second low-side switch are alternately turned on. As a result, a temperature of the motor generally reduces.

Abstract: An overvoltage protecting system and method of a motor pre-driver are provided. An overvoltage protecting circuit compares a first reference voltage with a common voltage inputted to a single phase motor to output a first comparison signal. When a controller circuit determines that the common voltage is higher than the first reference voltage according to the first comparison signal, the controller circuit turns off a first high-side switch and a second high-side switch, and turns on the first low-side switch and the second low-side switch, during a phase time of a phase transition signal of the single phase motor. After the phase time ends, the controller circuit alternately turns on the first low-side switch and the second low-side switch according to a level of the phase transition signal.

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: 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: An output buffer circuit with enhanced slew rate is disclosed. A first and a second slew-rate enhancing transistor are configured to enhance the slew rate of the source transistor and the sink transistor of an output stage. A first control circuit and a second control circuit turn off the first and the second slew-rate enhancing transistors during the static state, and turn on the first and the second slew-rate enhancing transistors during the transition.

Abstract: An output buffer circuit with enhanced slew rate is disclosed. A first and a second slew-rate enhancing transistor are configured to enhance the slew rate of the source transistor and the sink transistor of an output stage. A first control circuit and a second control circuit turn off the first and the second slew-rate enhancing transistors during the static state, and turn on the first and the second slew-rate enhancing transistors during the transition.