Device for preventing output of input signal, device for providing output voltage for driving motor, and motor driving system

The utility model discloses a device for preventing output of an input signal, a device for providing output voltage for a driving motor, and a motor driving system. The device for preventing output of the input signal comprises a signal control unit which comprises a signal buffer unit with an input end and an output end. The signal buffer unit is used for receiving the input signal in electrification and transmitting the signal to the output end. Power of the negative power end of the signal buffer unit is supplied by a first power supply. The signal control unit also comprises a voltage-boosting circuit which is used for boosting voltage of the first power supply so as to be higher than voltage of the first power supply. Besides, voltage of the first power supply or the boosted voltage is provided to the positive power end of the signal buffer unit. When the boosted voltage is provided to the positive power end of the signal buffer unit, the signal buffer unit is electrified. When voltage of the first powe