Switched-capacitor tracking apparatus of touch panel and operating method thereof

Abstract

A switched-capacitor tracking apparatus including a variable capacitor, an auxiliary capacitor, and a plurality of switches, and an operating method thereof are provided. In a charge period, a first reference voltage charges a panel capacitor, and a second reference voltage charges the variable capacitor. In a detection period, a control circuit detects a parallel connected voltage of the panel capacitor and the variable capacitor. The control circuit compares a third reference voltage and the parallel connected voltage. According to a comparison result, the control circuit dynamically determines whether to parallel connect the auxiliary capacitor to the variable capacitor. If all the comparison results accumulated in a statistics period are a first logic value, then the control circuit increases a capacitance of the variable capacitor. Moreover, if all the comparison results are a second logic value in the statistics period, then the control circuit decreases the capacitance of the variable capacitor.