Patent ID: 8810064

Claim:
A sequence control circuit for a power source, comprising: at least two switched circuits, for being coupled between the power source and a load to be powered by the power source, each of the switched circuits comprising a control node; and a sequence control unit comprising at least two output terminals, each of the output terminals being coupled to one of the control nodes, the output terminals generating control signals to control sequences of the switched circuits being turned on; wherein each one of the switched circuits comprises a first MOSFET and a second MOSFET, the first MOSFET has a drain coupled to the power source, a source coupled to the load and a gate coupled to a first constant voltage through a first resistor, the second MOSFET has a drain coupled to the gate of the first MOSFET, a source coupled to ground and a gate coupled to a second constant voltage through a second resistor and a third resistor, and one of the output terminals of the sequence control unit is coupled to a connecting node between the second resistor and the third resistor; and wherein in each one of the switched circuits, when the connecting node is provided with a high level signal, the second MOSFET is turned on and the first MOSFET is turned off; at that time, the switched circuit is turned off and a voltage at the power source is not supplied to the load; when the connecting node is provided with a low level signal, the second MOSFET is turned off and the first MOSFET is turned on; at that time, the switched circuit is turned on and the voltage at the power source is directly supplied to the load.