Integrated circuit with self-reference impedance

An integrated circuit with self-reference impedance, comprising:

• an input/output pin, provided for connection to an external impedance;
• a local impedance;
• a reference power circuit;
• a switching circuit, connected between the input/output pin, the local impedance and the reference power circuit, and configured to conduct a connection between the input/output pin and the reference power circuit in a first state and to conduct a connection between the local impedance and the reference power circuit in a second state;
• and
• a control circuit, configured to
• detect whether the input/output pin is connected to the external impedance or not and to generate a detection signal;
• and
• control the switching circuit into the first state or the second state according to the detection signal;
• wherein when the switching circuit is controlled into the first state, the reference power circuit generates a reference signal according to the external impedance, and when the switching circuit is controlled into the second state, the reference power circuit generates the reference signal as a reference power of the integrated circuit according to the local impedance.