A novel low-voltage low-power Second Generation Current Conveyor-based front-end for high-valued DC-excitated resistive sensors

In this work we present a new low-cost fully-integrable front-end, based on low voltage (LV) low power (LP) Second Generation Current Conveyors (CCIIs), for high-valued wide range resistive sensors which is able to evaluate the resistive behaviour of the utilized sensor without any preliminary calibration. This interface operates a resistance-to-time (R-T) conversion exciting the sensor with a DC voltage; it is able to reveal, for more than four decades of variation, both high and low resistive values. The proposed front-end has been designed using current mode techniques to work with a low-supply voltage (±0.75V) and a total of 0.7 mW power consumption, and hence it is suitable for low-cost portable applications. Cadence simulations on the designed integrated solution and experimental results, obtained using a discrete-component prototype board as interface, have shown output period with high linearity characteristics, so avoiding the need of any digital equalization.