Abstract: A current sensing circuit includes a filtering circuit, an amplifier, a first resistor, a first transistor and a second transistor. The filtering circuit is coupled to two terminals of a sensing resistor. The amplifier has a first input terminal, a second input terminal and an output terminal. The second input terminal is coupled to the filtering circuit. The first resistor is coupled between the filtering circuit and the first input terminal of amplifier. A control terminal of the first transistor is coupled to the output terminal of amplifier, and its first terminal is coupled to the first input terminal of amplifier and its second terminal is grounded through a second resistor. A control terminal of the second transistor is coupled to the output terminal of amplifier, and its first terminal is coupled to the second input terminal of amplifier and its second terminal is grounded through a third resistor.

Abstract: A current sensing circuit includes a filtering circuit, an amplifier, a first resistor, a first transistor and a second transistor. The filtering circuit is coupled to two terminals of a sensing resistor. The amplifier has a first input terminal, a second input terminal and an output terminal. The second input terminal is coupled to the filtering circuit. The first resistor is coupled between the filtering circuit and the first input terminal of amplifier. A control terminal of the first transistor is coupled to the output terminal of amplifier, and its first terminal is coupled to the first input terminal of amplifier and its second terminal is grounded through a second resistor. A control terminal of the second transistor is coupled to the output terminal of amplifier, and its first terminal is coupled to the second input terminal of amplifier and its second terminal is grounded through a third resistor.

Abstract: A current sensing circuit is provided. The current sensing circuit includes an amplifier, an input resistor, a sensing resistor, and a feedback circuit. The amplifier has a first input terminal, a second input terminal, a third input terminal, and an output terminal. The input resistor is coupled between the first input terminal and the second input terminal of the amplifier. The sensing resistor is coupled between the second input terminal and the third input terminal of the amplifier. The feedback circuit is coupled between the first input terminal and the output terminal. When an input current flows through the sensing resistor, a voltage across the sensing resistor is equal to a voltage across the input resistor, and the feedback circuit correspondingly outputs a sensing voltage according to the input current.

Abstract: A measuring current generation circuit coupled to a setting resistor is disclosed. The generation circuit includes a first measuring terminal, a second measuring terminal, a first transconductance amplifier, a second transconductance amplifier and an output circuit. The first transconductance amplifier has a first input terminal and a second input terminal. The first input terminal is coupled to one terminal of the setting resistor. The second input terminal is coupled to another terminal of the setting resistor and coupled to the first measuring terminal. The second transconductance amplifier has a third input terminal and a fourth input terminal. The output circuit is coupled to output terminals of the first transconductance amplifier and the second transconductance amplifier respectively and has a first output terminal and a second output terminal. The first output terminal is coupled to the first input terminal. The second output terminal is coupled to the second measuring terminal.

Abstract: A current sensing circuit is provided. The current sensing circuit includes an amplifier, an input resistor, a sensing resistor, and a feedback circuit. The amplifier has a first input terminal, a second input terminal, a third input terminal, and an output terminal. The input resistor is coupled between the first input terminal and the second input terminal of the amplifier. The sensing resistor is coupled between the second input terminal and the third input terminal of the amplifier. The feedback circuit is coupled between the first input terminal and the output terminal. When an input current flows through the sensing resistor, a voltage across the sensing resistor is equal to a voltage across the input resistor, and the feedback circuit correspondingly outputs a sensing voltage according to the input current.

Abstract: A measuring current generation circuit coupled to a setting resistor is disclosed. The generation circuit includes a first measuring terminal, a second measuring terminal, a first transconductance amplifier, a second transconductance amplifier and an output circuit. The first transconductance amplifier has a first input terminal and a second input terminal. The first input terminal is coupled to one terminal of the setting resistor. The second input terminal is coupled to another terminal of the setting resistor and coupled to the first measuring terminal. The second transconductance amplifier has a third input terminal and a fourth input terminal. The output circuit is coupled to output terminals of the first transconductance amplifier and the second transconductance amplifier respectively and has a first output terminal and a second output terminal. The first output terminal is coupled to the first input terminal. The second output terminal is coupled to the second measuring terminal.

Abstract: A filter and an operating method thereof are provided. The filter includes a logic circuit, a power circuit and a filter circuit. The logic circuit provides a switching control signal. The power circuit is coupled to the logic circuit. The filter circuit is coupled to the power circuit and the logic circuit. The filter circuit includes an amplifier, a first capacitor and a first transistor. An output end of the amplifier is coupled to the logic circuit, and provides an output signal. The first capacitor is coupled between an input end and output end of the amplifier. The first transistor is connected in parallel with the first capacitor. A control end of the first transistor is coupled to the power circuit. The logic circuit provides a switching control signal to the power circuit according to the output signal. The power circuit supplies a control voltage to the first transistor according to the switching control signal.

Abstract: A filter and an operating method thereof are provided. The filter includes a logic circuit, a power circuit and a filter circuit. The logic circuit provides a switching control signal. The power circuit is coupled to the logic circuit. The filter circuit is coupled to the power circuit and the logic circuit. The filter circuit includes an amplifier, a first capacitor and a first transistor. An output end of the amplifier is coupled to the logic circuit, and provides an output signal. The first capacitor is coupled between an input end and output end of the amplifier. The first transistor is connected in parallel with the first capacitor. A control end of the first transistor is coupled to the power circuit. The logic circuit provides a switching control signal to the power circuit according to the output signal. The power circuit supplies a control voltage to the first transistor according to the switching control signal.