Motor driving circuit and method thereof

Abstract

The invention discloses a motor driving circuit and a method thereof. The motor driving circuit includes a Hall sensor, an offset detecting circuit, a driving circuit and a back EMF zero point detector. The Hall sensor generates a Hall signal group, the offset detecting circuit detects the first phase changing point of the Hall signal group, and the driving circuit generates the initial phase changing signal in the pre-operation mode according to the Hall signal group. In the correction mode, the driving circuit stops outputting the initial phase changing signal, the back EMF zero detector detects the back EMF zero point, and outputs the back EMF zero point signal. The offset detecting circuit detects a phase difference between the first phase changing point and back EMF zero point, and determines a difference value between the phase difference and a predetermined phase difference. Then, the phase of the Hall signal group is adjusted according to the difference value.

Description

technical field [0001] The invention relates to a motor driving circuit and method, in particular to a motor driving circuit and method capable of automatically adjusting the phase of the Hall signal according to the phase difference between the counter electromotive force zero point and the Hall signal to eliminate the offset of the Hall component. Background technique [0002] The biggest feature of the brushless DC motor is the relationship between the brushless structure, and it does not generate noise in principle. This is not only mechanical noise, but also electrical noise. Furthermore, because there are no contact parts, it is easier to manufacture high-speed rotating motors. [0003] When driving a brushless DC motor, the Hall signal output by the Hall component is often used as the starting position of the sine wave. Under ideal conditions, when the Hall component has no installation tolerance, there is no phase difference between the back electromotive force, th...

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Problems solved by technology

[0004] However, in the actual manufacturing process, the placement tolerance of the Hall components will affect the quality of the mass production of the motor. For example, the Hall signal and the driving voltage are in the same phase, but the back electromotive force leads due to the installation tolerance of the Hall components. The drive voltage phase increases the feedback current, which in turn leads to power consumption of the brushless DC motor, making the efficiency of the brushless DC motor lower

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