Patent ID: 9577566
Date: 2017-02-21
CPC Classifications: H02P

Claim:
1. A motor driving circuit, adapted for driving a motor, and the motor driving circuit comprising: a full bridge circuit, electrically connected to the motor, and configured for receiving an input voltage; a control circuit, electrically connected to the full bridge circuit, and configured for controlling the phase commutation of the full bridge circuit according to a phase switching signal, to transform the input voltage into a plurality of driving voltage signals in the full bridge circuit and to accordingly control the operation of the motor; a sensor-less controller, configured for receiving the driving voltage signal, to sense the phase of the driving voltage signals, and to accordingly output a first switching signal; a hall control device, having a hall positive terminal and a hall negative terminal, the hall positive terminal configured for receiving a first hall signal, the hall negative terminal configured for receiving a second hall signal, and the hall control device configured for outputting a second switching signal according to the first hall signal and the second hall signal; and a select circuit, electrically connected to the sensor-less controller and the hall control device, and configured for selecting the first switching signal as the phase switching signal or selecting the second switching signal as the phase switching signal according to the first hall signal and the second hall signal, the select circuit comprises: wherein the hall positive terminal is electrically connected to a voltage source, to generate the first hall signal more than or equal to the reference voltage, or the hall negative terminal is electrically connected to the voltage source, to generate the second hall signal more than or equal to the reference voltage.