Offset compensation for differential charge‐based capacitance measurement

Abstract

SummaryThis paper presents a fully integrated differential charge‐based capacitance measurement (CBCM) circuit designed to detect attoFarads capacitive variations to find airborne particulate matter (PM). This paper presents a novel method for compensating the output offset of the CBCM electronic front‐end in the range of 3.1–3.4 V through the trimming of the bulk voltage of key transistors of the circuit topology. Experimental results on prototypes implemented using a 130‐nm CMOS technology and driven by a 100‐MHz clock confirm the validity of the proposed approach.