Abstract
Detecting sunlight or ultraviolet (UV) radiation in consumer electronic devices, such as wearable devices or hearables, can involve dedicated components like photodiodes and associated circuitry, which may add to cost and device complexity. This disclosure describes a system that may repurpose existing hardware for optical sensing. The technique can use a capacitive sensing circuit, such as a capacitive touch integrated circuit, to measure a change in capacitance of a component like a transient voltage suppressor (TVS) diode when exposed to light. Upon illumination, a photovoltaic effect within the diode's p-n junctions may increase its junction capacitance, a change that can be detected by the capacitive sensing circuit. Further, a UV bandpass filter may be placed over the TVS diode to facilitate the specific detection of UV light density. This approach may allow for sunlight and UV detection in products already containing a capacitive touch system, potentially reducing component count and saving space, which could be useful for various applications.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Recommended Citation
Chen, Barry and Wang, Mike, "System and Method for Optical Sensing Using Capacitance Measurement of an Electronic Component", Technical Disclosure Commons, (October 15, 2025)
https://www.tdcommons.org/dpubs_series/8722