| 摘要 |
A closed-loop switched capacitor power supply converts a supply voltage into an output voltage that rapidly approaches a set-point voltage by using a variable frequency source, a switched capacitor network and a feedback control circuit. The variable frequency source provides the switched capacitor network with a control voltage having a control frequency that affects the impedance of the switched capacitor network. The switched capacitor network comprises one or more network sections, each one having a grounded capacitor with the other terminal coupled to a supply voltage through a first switch and coupled to the load through a second switch. The first and second switches work in a complementary manner, such that when the first switch is closed the capacitor is charged by the supply voltage, and when the second switch is closed the capacitor discharges into the output of the switched capacitor network. The feedback control circuit is coupled to the output of the switched capacitor network and uses a proportional integral/derivative compensator to regulate the control frequency of the variable frequency source in accordance with the difference between the output voltage and the set-point value. In this way, the output voltage of the power supply can be controlled by varying the frequency of the control voltage of the variable frequency source. Embodiments with additional capacitor networks are advantageous as output ripple is reduced and the overall energy efficiency of the circuit is increased. The power supply is also capable of measuring the power consumption of the load with high accuracy.
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