Analog compensation of parasitic sensor signals in a subsampling impedance analyzer circuit for resonating sensors

Many sensor signals are afflicted with unwanted components induced by parasitic but well known sensor effects. With utilization of digitizing interface circuits the suppression of these components is typically performed in the digital domain. Hence the effective resolution of the system is reduced, especially when unwanted signal components are dominating the signal’s magnitude. In this contribution, a method of parasitic signal compensation as implemented in an impedance analyzer circuit for a quartz crystal resonating sensor is presented.