Ultra-Low Power Wide-Dynamic-Range Universal Interface for Capacitive and Resistive Sensors

Abstract

This paper presents an ultra-low power, wide-dynamic-range interface circuit for capacitive and resistive sensors. It is implemented as a switched-capacitor circuit using tunable capacitors to achieve high configurability. The circuit was fabricated using a 0.18μm CMOS technology. Measured results show that the circuit is able to interface various sensors within the overall capacitance range of 0.6–550pF and resistance range of 3.7kΩ–5.1MΩ, while consuming only 0.39–3.56μW, from a 1.2V supply.