Readout electronics with calibration and on-line test for resistive sensor bridges

In this paper a digitally programmable readout electronics for resistive sensor bridges is presented together with an efficient method for calibration based on the principle of piecewise linear interpolation. The calibration enables a temperature compensation in the range between -40øC and +120øC. The architecture also allows an automatic calibration process with a minimum expenditure of external hardware. In addition the system contains an implemented function for monitoring the resistive sensor bridge condition during operation. For automotive applications an integrated voltage regulator is available so that the chip can optionally operate either at a stabilized 5V power supply voltage or use an unregulated voltage in the range between 7.5V and 16V.