| 主权项 |
1. An input circuit comprising:
a first input terminal that receives a first input signal; a second input terminal that receives a second input signal that is phase-reversed from the first input signal; a first capacitor with a first end connected to the first input terminal and a second end connected to a first node; a second capacitor with a first end connected to the second input terminal and a second end connected to a second node; a reference voltage generating circuit that generates a reference voltage and supplies the voltage to a reference node; a first resistor connected between the first node and the reference node; a second resistor connected between the second node and the reference node; a first switch connected in series with the first resistor between the first node and the reference node; a second switch connected in series with the second resistor between the second node and the reference node; a differential receiving circuit with a first input connected to the first node and a second input connected to the second node, the differential receiving circuit receiving differential signals inputted to the first input and the second input and outputting a single-phase output signal; a first switch control circuit that controls the first switch and the second switch; a first signal detecting circuit that receives the first input signal through the first input terminal and the second input signal through the second input terminal, and outputs a first detection signal based on the first input signal and the second input signal; and a second signal detecting circuit that receives the output signal of the differential receiving circuit and outputs a second detection signal based on the output signal, wherein the first switch control circuit turns off the first switch and the second switch in a first period during which the first input signal and the second input signal are DC signals, and the first switch control circuit turns on the first switch and the second switch in a second period during which the first input signal and the second input signal are AC signals, wherein the first signal detecting circuit outputs the first detection signal when the first signal detecting circuit detects that the first input signal and the second input signal are the DC signals, and the first switch control circuit turns off the first switch and the second switch in response to the first detection signal, and wherein the second signal detecting circuit outputs the second detection signal when the second signal detecting circuit detects that the output signal is the AC signal, and the first switch control circuit turns on the first switch and the second switch in response to the second detection signal. |
