Circuit with calibration function and circuit calibration method

A circuit calibration method, comprising:

• amplifying a pair of differential input voltages to generate a pair of differential output voltages;
• utilizing a first current to flow through a capacitor to generate a first voltage;
• utilizing a second current to flow through a resistor to generate a second voltage;
• providing the pair of differential output voltages or the first and second voltages to a comparator according to a digital control signal, such that the comparator compares the pair of differential output voltages or the first and second voltages to provide a comparison signal;
• and
• generating a first digital code or a second digital code according to the comparison signal, wherein the first digital code is used to adjust a capacitance of the capacitor and the second digital code is used to adjust DC voltage levels of the pair of differential output voltages.

A circuit with calibration function, the circuit comprising:

• a fully differential amplifier circuit having a first input terminal, a second input terminal, a first output terminal, and a second output terminal;
• a first capacitor coupled between the first input terminal and the second output terminal through a first switch;
• a first resistor coupled between the first input terminal and the second output terminal;
• a second capacitor coupled between the second input terminal and the first output terminal;
• a second resistor coupled between the second input terminal and the first output terminal through a second switch;
• a first current source coupled to the first input terminal through a third switch;
• a second current source coupled to the second input terminal through a fourth switch;
• a first multiplexer coupled to the first input terminal and the second output terminal;
• a second multiplexer coupled to the second input terminal and the first output terminal;
• a comparator coupled to an output terminal of the first multiplexer and an output terminal of the second multiplexer to provide a comparison signal;
• and
• a digital logic circuit coupled to the comparator to receive the comparison signal;
• wherein in an RC time constant calibration mode, the first multiplexer and the second multiplexer provide a signal of the first input terminal and a signal of the second input terminal to the comparator according to a digital control signal, and the digital logic circuit generates a first digital code according to the comparison signal to adjust a capacitance of the second capacitor.