Voltage-regulating circuit with input voltage detecting circuit and parallel voltage-regulating circuit system using the same

A parallel voltage-regulating circuit system comprising:

• plural voltage-regulating circuits, wherein plural voltage-regulating circuits are parallel, and each of said voltage-regulating circuits comprises:
• a power conversion circuit comprising at least one switch element, wherein during operation of said at least one switch element, an input voltage is converted into a transition voltage with an output current;
• an input voltage detecting circuit connected to said power conversion circuit for outputting a detected voltage signal corresponding to said input voltage;
• a current-detecting circuit connected to said power conversion circuit for outputting a detected current signal corresponding to said output current;
• a feedback circuit connected to said power conversion circuit, said current-detecting circuit and said input voltage detecting circuit, wherein said feedback circuit receives said transition voltage, said detected voltage signal and said detected current signal, and generates a feedback control signal according to said transition voltage, said detected voltage signal and said detected current signal;
• and
• a control driving circuit connected to said switch element and said feedback circuit for receiving said feedback control signal, and controlling a duty cycle of said switch element to be higher than a preset duty cycle according to said feedback control signal;
• wherein as said input voltage is changed, said feedback circuit will adjust to make said transition voltage changed as with the change of said detected voltage signal corresponding to said input voltage.

A parallel voltage-regulating circuit system comprising:

• plural voltage-regulating circuits, wherein plural voltage-regulating circuits are parallel and connected together by a current sharing bus, and each of said voltage-regulating circuits comprises:
• a power conversion circuit comprising at least one switch element, wherein during operation of said at least one switch element, an input voltage is converted into a transition voltage with an output current;
• an input voltage detecting circuit connected to said power conversion circuit for outputting a detected voltage signal corresponding to said input voltage;
• a current-detecting circuit connected to said power conversion circuit for outputting a detected current signal corresponding to said output current;
• a feedback circuit connected to said power conversion circuit, said current-detecting circuit and said input voltage detecting circuit, wherein said feedback circuit receives said transition voltage, said detected voltage signal and said detected current signal, and generates a feedback control signal according to said transition voltage, said detected voltage signal and said detected current signal;
• and
• a control driving circuit connected to said switch element and said feedback circuit for receiving said feedback control signal, and controlling a duty cycle of said switch element to be higher than a preset duty cycle according to said feedback control signal;
• wherein as said input voltage is changed, said feedback circuit will adjust to make said transition voltage changed as with the change of said detected voltage signal corresponding to said input voltage;
• and
• wherein as said detected current signal is not equal to a signal on said current sharing bus, said feedback circuit will adjust to make said detected current signal equal to said signal on said current sharing bus.