Control circuit of motor and control method thereof

The invention discloses a control circuit of a motor and a control method thereof. The control circuit includes a low-voltage sub-circuit, a high-voltage sub-circuit, and an isolated gate therebetween. The low-voltage sub-circuit comprises a current controller suitable for generating a driving signal and a feedback loop, and the output of the feedback loop is fed back to the input end of the current controller. The high voltage sub-circuit is adapted to output a current for driving the motor, analog front end and ADC. The isolated gate includes an isolator adapted to pass an output signal of the ADC from the high voltage sub-circuit through the isolated gate to the low voltage sub-circuit. The analog front end is adapted to apply a low or high gain as a function of the current in at least one phase. The isolator includes a first channel and a second channel that pass a clock signal and a control signal from the low voltage sub-circuit to the high voltage sub-circuit, respectively, to select a low gain or a hi