Patent ID: 8653695

Claim:
A power switching device, comprising: a first switch, for receiving a first power and determining whether to output the first power as an output voltage according to a first switching signal; a second switch, for receiving a second power and determining whether to output the second power as the output voltage according to a second switching signal; and a switch unit, coupled to the first switch and the second switch, for comparing a voltage level of the first power and a voltage level of the second power and outputting the first switching signal and the second switching signal to turn on at least one of the first switch and the second switch, wherein the switch unit comprises: a first current transducer, for receiving the first power and outputting the first power to the first switch and a first current corresponding to the first power; a second current transducer, for receiving the second power and outputting the second power to the second switch and a second current corresponding to the second power; a hysteresis voltage comparator, coupled to the first current transducer and the second current transducer, for receiving and comparing the voltage level of the first power and the voltage level of the second power and outputting a first comparison signal; a current comparator, coupled to the first current transducer and the second current transducer, for receiving and comparing the first current and the second current and outputting a second comparison signal; and a logical operation unit, coupled to the first switch, the second switch, the hysteresis voltage comparator, and the current comparator, for receiving the first comparison signal and the second comparison signal to perform a logical operation, and thereby outputting the first switching signal and the second switching signal.