Multiphase motor driving circuit and multiphase motor driving method

A multiphase motor driving circuit, comprising:

• a power stage circuit, coupled between a holding voltage and a multiphase motor, wherein the power stage circuit is configured to operate the multiphase motor according to a pulse width modulation (PWM) signal;
• and
• a control circuit, configured to generate the PWM signal based on power supplied by the holding voltage;
• wherein, in a motor braking mode, when the holding voltage is less than a first voltage threshold, a first sub-mode is entered, wherein in the first sub-mode, the control circuit controls at least a portion of plural switches in the power stage circuit to switch periodically utilizing the PWM signal, thereby converting a back electromotive force (EMF) of the multiphase motor into the holding voltage, which is subsequently used to supply power to the control circuit;
• wherein, in the motor braking mode, when the holding voltage is greater than a second voltage threshold, a second sub-mode is entered, wherein in the second sub-mode, the control circuit controls at least a portion of the plural switches in the power stage circuit to remain continuously conductive utilizing the PWM signal, thereby consuming the back EMF of the multiphase motor, so as to reduce a rotation speed of the multiphase motor.