A proposal to eliminate the impact of crosstalk on resistive sensor array readouts

Abstract

Completely eliminating crosstalk effect is the most important challenge when reading a resistive sensor array with M rows and N columns. It may require complex electronics, ranging from a large number of multiplexers and switches to use of M AC voltage sources. More measurements than those considered strictly necessary, M · N, may also be required. Thus, an implementation with multiplexers and switches uses 2 · M · N measurements, while this number rises to M · N · L in the one that uses AC voltage sources, where L is the Fourier Transform length required to obtain the sensor readings. This article presents a new circuit and readout method to eliminate crosstalk that simultaneously reduces the total number of multiplexers to M + N and the number of measurements to N · (M + 1 + (N + 1)/2). The unique source of error comes from the non-idealities of the only operational amplifier used. As an added benefit, the new circuit also reduces power consumption of the array by including a single additional resistor.