Offset compensation for differential charge-based capacitance measurement

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. image