摘要 |
A two-stage switching power supply includes a first-stage power circuit, a bus capacitor, a second-stage power circuit and a power control unit. The first-stage power circuit is connected to a power bus for receiving an input voltage, and includes a first switching circuit. The input voltage is converted into a bus voltage by alternately conducting and shutting off the first switching circuit. The second-stage power circuit is connected to the power bus for receiving the bus voltage, and includes a second switching circuit. The power control unit is used for controlling operations of the first switching circuit and the second switching circuit. The bus voltage is dynamically adjusted according to electricity consumption amount of the system circuit under control of the power control unit. An operating mode of the second switching circuit of the second-stage power circuit is changed according to the electricity consumption amount of the system circuit.
|