6.7 A 2.3mW 11cm-range bootstrapped and correlated-double-sampling (BCDS) 3D touch sensor for mobile devices

Contactless (3D) touch sensors, when integrated with displays, offer many advantages over that of conventional touch-panel screens by offering a more hygienic and a more immersive & interactive human/machine interface for 3D user experiences [1]. While significant progress has been made in developing 3D contactless touch sensors for larger television and monitor type displays [2-3], the technology has yet to be infused into space- and battery-constrained mobile devices (i.e., tablets and smartphones). For successful insertions into these systems, a paradigm shift in touch-sensor system design is essential to enable seamless sensing operations with smaller-size, more tightly spaced, strongly coupled, and highly resistive display electrodes. In addition, any successful 3D sensing solution for mobile devices must consume low power and small silicon area to be compatible with limited battery and space resources.