A Current-Mode Position Sensitive Circuit

A novel technique to implement mesh-type position sensitive devices using current-mode analog VLSI is presented. By taking advantage of local analog computation this approach allows to create extremely compact circuit implementations. While in conventional approaches most sensor characteristics are adjusted by setting process parameters, our technique is fully electronically tunable and suitable to be implemented in general purpose CMOS technology. We have verified experimentally our idea designing and fabricating via MOSIS a 20 element 1D position circuit. Test results are presented demonstrating nonlinearity below 2.2% for currents in the range of 5pA to 10nA.