Nuvoton Technology Corporation

Chung-He Li

Yeh-Tai Hung

Chung Ming Hsieh

A protection circuit is adapted to a switching-capacitor regulation circuit having a capacitor. The protection circuit comprises a current source, first and second switch circuits, and a control unit. First, the control unit turns on the second switch circuit to make a top end and a bottom end of the capacitor, and control the first switch circuit to make the current source no connect the capacitor, and then set a voltage of the top and the bottom to be a first preset voltage. Next, the control unit turns off the second switch circuit to disconnect the top end and the bottom end, and turn on the first switch circuit to flow current from the bottom end of the capacitor. When a voltage difference between the top end and the bottom end is equal to a preset initial voltage, the control unit control the first switch circuit to disconnect the current source and the capacitor; next, the control unit controls current flow in or out from the top of the capacitor based on the voltage on the top of the capacitor.

Protection circuit and operation method thereof

A startup circuit initializes a voltage of a capacitor of a switch-capacitor regulator. The startup circuit includes a voltage forming circuit and a control unit. The voltage forming circuit selectively electrically connected to the top and the bottom of the capacitor. In a first operation phase, the voltage forming circuit is electrically connected to the top and bottom of the capacitor, and the top and bottom of the capacitor are connected to each other, and the voltages of the top and bottom are set as a preset high voltage. In a second operation phase, the voltage forming circuit disconnects the top and the bottom, and generates current flowing out from the bottom of the capacitor until the voltage cross the capacitor is equal to the preset initial voltage. In the third operation phase, the startup circuit is disconnected from the capacitor.

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Hsinchu, Taiwan

Chung-He Li