| 摘要 |
A control circuit (120, 140) for a brushless direct current (DC) motor (160) includes a current drive circuit (140), a current loop regulator (122), and a commutation loop regulator (124, 126). The current drive circuit (140) is adapted to drive the brushless DC motor (160) in a first polarity or a second polarity selectively in response to a control signal, and senses a current through the brushless DC motor (160) to provide a current sense signal. The current loop regulator (122) varies a duty cycle of the control signal to regulate the current in response to the current sense signal, and regulates the polarity of the current based on a state of a polarity signal. The commutation loop regulator (124, 126) regulates a transition of said polarity signal in response to a comparison of a pre-commutation duty cycle value and a post-commutation duty cycle value.
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