Offset compensation for differential charge‐based capacitance measurement

Summary This 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. The paper discusses a novel offset compensation technique for the Charge‐Based Capacitive Measurement (CBCM) method. The proposed solution involves adjusting the threshold voltage of PMOS transistors to correct mismatches, enhancing circuit performance without additional hardware.