| CPC H02M 1/32 (2013.01) [H02M 1/0009 (2021.05); H02M 1/083 (2013.01)] | 14 Claims |
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1. A power converter having an overvoltage protection mechanism, comprising:
a switch circuit including a high-side switch and a low-side switch, wherein a first terminal of the high-side switch is connected to an input power source, a first terminal of the low-side switch is connected to a second terminal of the high-side switch, a second terminal of the low-side switch is grounded, a node between the second terminal of the high-side switch and the first terminal of the low-side switch is connected to a first terminal of an inductor, a second terminal of the inductor is connected to a first terminal of an output capacitor, and a second terminal of the output capacitor is grounded;
a driver circuit connected to a control terminal of the high-side switch, a control terminal of the low-side switch and the input power source;
a control circuit connected to the driver circuit and the input power source; and
an overvoltage protecting circuit connected to the input power source and the first terminal of the inductor;
wherein, when releasing energy at an output node between the second terminal of the inductor and the first terminal of an output capacitor, the control circuit controls the driver circuit to turn on the high-side switch, and an output current of the power converter flows from the output node sequentially through the inductor and the high-side switch to the input power source;
wherein, when the overvoltage protecting circuit determines that a voltage or a current at the first terminal of the inductor or a voltage or a current of the input power source is larger than a threshold, a part of the output current of the power converter flows from the output node sequentially through the inductor and the high-side switch to the input power source, and other parts of the output current of the power converter flow from the output node through the overvoltage protecting circuit to a ground;
wherein the overvoltage protecting circuit further includes a first transistor and a plurality of second transistors, a first terminal of one of the plurality of second transistors is connected to the input power source, a second terminal and a control terminal of the one of the plurality of second transistors are connected to a control terminal of the first transistor, a second terminal of another of the plurality of second transistors is grounded, a first terminal of the other of the plurality of second transistors is connected to a second terminal of the second transistor disposed adjacent thereto, and the control terminal and the second terminal of each of the plurality of second transistors are connected to each other.
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