Error model for a sensor interface system based on the 1st order delta-sigma modulator due to the nonlinearity of the sensor

摘要

A sensor is an analogue element that mostly has nonlinearity characteristics. Integrating the sensor as the delta element in a delta sigma modulator system enables to interface the sensor in a small and compact system. Due to the nonlinearity of the sensor, a new problem is being introduced to the delta sigma modulator system. To minimize this particular problem, the system is normally designed by limiting the feedback signal which means also limiting the dynamic range of the system. This paper introduces an error model that can estimate the error caused by implementing the sensor in the modulator. The model achieves up to 99.9% accuracy.