Driving circuit for motor systems and control method thereof

A driving circuit for a motor, comprising:

• a first bridge circuit and a second bridge circuit, coupled in parallel between an input voltage and a ground to provide a driving current for the motor, the first bridge circuit comprises a first high-side switch and a first low-side switch coupled in series, and the second bridge circuit comprises a second high-side switch and a second low-side switch coupled in series, wherein a first common node voltage is developed at a common node of the first high-side switch and the first low-side switch, and a second common node voltage is developed at a common node of the second high-side switch and the second low-side switch;
• and
• a reverse current control circuit, configured to determine whether to control the first low-side switch or the second low-side switch to work in a low-dropout linear regulation (LDO) mode, and wherein
• when the first common node voltage is chosen based on a hall sense signal, and when the first common node voltage is larger than the input voltage and a polarity indication signal indicates that a polarity of the driving current changes from positive to negative, the first low-side switch is configured to work in the LDO mode;
• and wherein
• when the second common node voltage is chosen based on the hall sense signal, and when the second common node voltage is larger than the input voltage and the polarity indication signal indicates that the polarity of the driving current changes from negative to positive, the second low-side switch is configured to work in the LDO mode.

A control method for a driving circuit with a first bridge circuit and a second bridge circuit coupled in parallel between an input voltage and a ground to provide a driving current for a motor, the control method comprising:

• choosing a first common node voltage at a common node formed by a first high-side switch and a first low-side switch of the first bridge circuit or a second common node voltage at a common node formed by a second high-side switch and a second low-side switch of the second bridge circuit as a chosen common node voltage based on a hall sensing signal;
• and
• determining whether to control the first low-side switch or the second low-side switch to work in a low-dropout linear regulation (LDO) mode;
• and wherein
• when the first common node voltage is chosen, and when the first common node voltage is larger than the input voltage and a polarity indication signal indicates that a polarity of the driving current changes, controlling the first low-side switch to work in the LDO mode;
• and
• when the second common node voltage is chosen, and when the second common node voltage is larger than the input voltage and the polarity indication signal indicates that the polarity of the driving current changes, controlling the second low-side switch to work in the LDO mode.