Data Conversion and Programmable Calibration for Smart Sensors

In this paper we present a new architecture for a smart sensor interface. It is based on an oversampled A/D converter associated with a small ROM containing calibration coefficients. The non-linear function desired is obtained by piecewise linear interpolation between the values stored in the ROM. This solution has the advantages of high programming flexibility, long-term stability and low area consumption. Moreover it is suitable for co-integration with sensors because of its minimum analog content. Simulation and experimental results are reported together with a detailed theoretical analysis and some design guidelines.