A High Accuracy Readout Circuit for Resistor Array

This article presents a new method for measuring two dimensional piezoresistive arrays, reducing operational amplifier (opamp) usage while enhancing measurement accuracy. The offset voltage of opamp causes significant current crosstalk in the array readout circuit, reducing measurement accuracy. To reduce errors caused by opamps, a method using fewer opamps and modifying the power supply excitation is proposed. As a result, the precision of resistance measurements is enhanced without increasing circuit complexity. Theoretical analysis has demonstrated that this design can enhance both the stability and accuracy of the measurement. Simulation analysis verified that this approach can achieve higher measurement accuracy than the zero potential method (ZPM) on a 16 × 16 resistor array as the mean, variance, and coefficient of variation of the offset voltage of the opamps are adjusted, and can reduce errors by more than 50%. Both theoretical study and simulation analysis were validated through experimental measurements.