A Delta-Sigma ADC for Column-Parallel Mutual-Capacitive Touch Sensor

Abstract

This research presents a delta-sigma analog-to-digital converter for column-parallel mutual-capacitive touch sensor. A small-area low-power second-order single-bit delta-sigma modulator and a sinc3 decimation filter were designed in a 0.35μm process. The area of the single delta-sigma modulator is 680μm x 170um. The ENOB values in simulation are 15.2-bit and 17.1-bit for the OSR at 256 and 512, respectively. The ENOB values in measurement are 10.4-bit and 12.3-bit for the OSR at 256 and 512, respectively.