A low-power wide-range interface circuit for nanowire sensor array based on resistance-to-frequency conversion technique

A traditional oscillator approach which implements the resistance-to-frequency conversion is shown to be effectively used as interface circuit for nanowire sensor array. The interface readout circuit is configurable in terms of output frequency and achieves a highly linear detection range over sensor resistance of 1MΩ to 1GΩ without any calibration system. A three-bit digitally-controlled current-starved ring oscillator is presented to oversample the resistance-to-frequency conversion result for following data processing.