Resistance-Capacitance Calibration Circuit without Current Mismatch and Method thereof

摘要

A resistor-capacitor (RC) calibration circuit includes: a current source, providing a current to a first node; a first switch, coupled between the first node and a second node; a second switch, coupled between the first node and a third node; a resistor, coupled between a reference terminal and the second node; a variable capacitor, coupled between the reference terminal and the third node; a third switch, coupled between the third node and the reference terminal; a comparator, comprising a first input coupled to the second node and a second input coupled to the third node; and a logic controller, coupled between an output of the comparator and the variable capacitor for outputting an adjusting signal according to an output signal of the comparator to adjust a capacitance of the variable capacitor.