Patent ID: 9484920
Filing Date: 2016-11-01
CPC Classification: H03K,H04N

Claim Text:
1. A switching circuit, comprising a comparator circuit, a first switch circuit, a second switch circuit, a first drive voltage source, and a second drive voltage source, wherein the comparator circuit comprises a first input end, a second input end, and an output end; the first switch circuit and the second switch circuit both comprise an input end, an output end, and a drive end; the first input end of the comparator circuit is configured to receive an input voltage; the second input end of the comparator circuit is configured to receive a reference voltage; the output end of the comparator circuit is separately connected to the input end of the first switch circuit and the input end of the second switch circuit; the drive end of the first switch circuit is connected to the first drive voltage source; the drive end of the second switch circuit is connected to the second drive voltage source; the comparator circuit is configured to determine whether the input voltage is greater than the reference voltage; output a high level if it is determined that the input voltage is greater than the reference voltage; and output a low level if it is determined that the input voltage is not greater than the reference voltage; the first switch circuit is configured to, when the comparator circuit outputs the high level, switch on and output, by using the output end of the first switch circuit, a first drive voltage provided by the first drive voltage source; and switch off when the comparator circuit outputs the low level; and the second switch circuit is configured to, when the comparator circuit outputs the low level, switch on and output, by using the output end of the second switch circuit, a second drive voltage provided by the second drive voltage source; and switch off when the comparator circuit outputs the high level, wherein the first switch circuit comprises a first NPN transistor and a first P-channel field-effect transistor, the first NPN transistor is configured to receive output of the comparator circuit to control conductance of the first P-channel field-effect transistor, and thus control conductance of the first switch circuit, wherein the second switch circuit comprises a second NPN transistor, a third NPN transistor and a second P-channel field-effect transistor, the second NPN transistor is configured to receive the output of the comparator circuit to control conductance of the third NPN transistor and the second P-channel field-effect transistor, and thus control the conductance of second switch circuit.