Analog-to-digital converter, touch sensing chip and electronic device

Abstract

An analog-to-digital converter, a touch sensing chip and an electronic device are disclosed. The ADC includes a digital-to-analog conversion circuit, a comparator, a successive approximation register logic circuit and a residue sampling and summing circuit, the successive approximation register logic circuit coupled to output terminal of the comparator and control terminal of the digital-to-analog conversion circuit, the successive approximation register logic circuit configured to produce a corresponding quantized digital signal each time, based on the result of comparison from the comparator, the residue sampling and summing circuit configured to obtain a corresponding residue each time, by sampling residual voltage output from digital-to-analog conversion circuit, sum previous sampled residue and common reference voltage and provide the sum to the comparator, the comparator configured to compare a current output of the residue sampling and summing circuit with a current output of the digital-to-analog conversion circuit and thereby obtain current result of comparison.