Surge protection circuit and communication device using the same

Abstract

The present disclosure relates to a surge protection circuit and a communication device using the same. The surge protection circuit is coupled between an input voltage source and a circuit to be protected. The surge protection circuit includes: a first capacitor, configured to receive the input voltage source; an inductor, coupled to the first capacitor; and a switching circuit coupled to the first capacitor, the inductor, and the circuit to be protected. The switching circuit includes a first switch and a second switch, wherein the first and second switches share a common gate and are connected to the first capacitor. In response to a surge appearing at the input voltage source: the equivalent impedance of the first capacitor is reduced; the equivalent impedance of the inductor is increased; the surge is directed through the first capacitor, causing the first switch to remain off, thereby blocking the surge from reaching the protected circuit; and the surge turns on the second switch through the first capacitor, guiding the surge to a ground terminal.

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