A Proposal to Eliminate the Impact of Crosstalk on Resistive Sensor Array Readouts

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, ${M}\,\cdot {N}$ , may also be required. Thus, an implementation with multiplexers and switches uses $2\,\cdot {M}\,\cdot {N}$ measurements, while this number rises to ${M}\,\cdot {N}\,\cdot {L}$ 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 ${N}\,\cdot ({M}+1+({N}+1$ )/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.