Linear Readout Circuit for Simultaneously Accessing Two Elements in the Two-Dimensional Resistive Sensor Array

Most readout circuits of the two-dimensional resistive sensor array (2-D RSA) have a non-linear relationship between the output voltage and the resistance of the element being tested (EBT), which will cause extra measurement error for the finite precision of the analog-to-digital converter. Firstly, we designed a novel linear readout circuit based on double voltage feedback loops (LRC-DVFL) which could access two elements in the array simultaneously, and the output voltages had a linear relationship with the resistances of the EBTs. Then, the approximate circuit model of the LRC-DVFL was derived and the mathematical equivalent resistance expressions of the EBTs were derived in Appendix. Followed, the simulation experiments and the test experiments with a prototype circuit of the LRC-DVFL were carried out. Experimental results show that the LRC-DVFL can access two elements in the 2-D RSA simultaneously with linear output voltages, and the performance of the LRC-DVFL can be evaluated quickly by using the mathematical equivalent resistance expressions of the EBTs.