A smart all-digital charge to digital converter

Abstract

Capacitance sensors, that report the values of capacitances as digital codes, are important in such areas as biomedical, environmental, and mobile applications. Voltage sensors are also widely used in many modern application areas, e.g. where battery life information is important. Conventional capacitance sensing methods use complex ADC techniques that are power hungry, and existing digital solutions, which use the charge to digital conversion (CDC) method tend to suffer from slow sensing response. A novel dual-use all-digital CDC method is proposed in this paper, which can be used to sense either capacitance values as a capacitance sensor or voltage levels as a voltage sensor. It shows low power/energy consumption and fast sensing response.