Motor driving circuit with power reversal protection and fan device

A fan device, comprising:

• a blade;
• a motor, configuring the blade, and driving the blade to rotate;
• a motor driving circuit, electrically connected to the motor, and comprising:
• a full bridge circuit, electrically connected between the motor and a ground end;
• a control circuit, electrically connected to the full bridge circuit, and configured for controlling the phase commutation of the full bridge circuit according to two hall signals, to generate a plurality of driving voltage signals in the full bridge circuit and to accordingly control the operation of the motor;
• and
• a reversal protection circuit, electrically connected among a supply end, the full bridge circuit, and the control circuit, and the reversal protection circuit comprising:
• a LDMOS, having a drain end, source end, and a gate end, the drain end electrically connected to the supply end, and the source end electrically connected to the full bridge circuit;
• a voltage pull-down element, electrically connected between the gate end and the ground end, and used for decreasing the voltage of the gate end;
• and
• a zener diode, having an anode end and a cathode end, the anode end connected to the gate end, and the cathode end connected to the full bridge circuit, and the zener diode used for limiting the voltage of the gate end to being above a clamp voltage, so that the voltage difference between the source end and the gate end is less than a predefined low voltage;
• wherein when the supply end is connected to ground through a ground line of a power supply and the ground end receives a power generated from a power line of the power supply, the voltage difference between the source end and the gate end is less than a turn-on voltage, to turn off the LDMOS.