Resistive sensor arrays have been increasingly utilized in physical variables measuring. Row-column method is a conventional way for resistive sensors connections. However, the non-idealities of the operational amplifiers, switches and wires reduce the accuracy of the circuit. In this paper, the effect of non-idealities on crosstalk error is analyzed and a new method has been proposed to reduce all nonideality effects simultaneously. The proposed circuit reduces the measuring error by using only two additional buffers. The results of theoretical analysis, simulation and measurement confirm that the proposed method can improve the accuracy. Simulation results of 8×8 array for a 100Ω non-scanned resistance show that the worst-case measuring error is decreased to 0.025%. For a 32Ω resistance of row selection switches and a 32Ω resistance of columns wires, the error is reduced to 0.000027% and 0.00049%, respectively. Also, the simulation results for a 32×32 array shows the maximum error of 0.0005% in the array. Furthermore, an 8×8 resistive array has been designed and implemented which the measurement results confirm that for a 30.9Ω resistance of row selection switches and a 30.9Ω resistance of columns wires, the error is reduced to 0.033% and 0.308%, respectively.

Keywords