Patent ID: 9748889
Date: 2017-08-29
CPC Classifications: H02P

Claim:
1. A shutdown method for motor, comprising: (A) shutting down a higher gate switch and a lower gate switch when a supply voltage decreases to make a storage capacitor lower than a first threshold voltage, such that the storage capacitor is charged via a back electromotive force, wherein the back electromotive force decreases as the motor gradually stops; (B) driving the motor when the voltage of the storage capacitor is again larger than the first threshold voltage, such that the storage capacitor starts to discharge; (C) determining whether the voltage of the storage capacitor is lower than a shutdown threshold voltage when the voltage of the storage capacitor is lower than the first threshold voltage, wherein the shutdown threshold voltage is lower than the first threshold voltage; and (D) turning on the lower gate switch when the voltage of the first threshold voltage is lower than the shutdown threshold voltage, such that a back current flows to the lower gate switch, wherein the back current is related to the back electromotive force.