A high-accuracy temperature sensor with second-order curvature correction and digital bus interface

A high-accuracy CMOS temperature sensor with integrated bus interface is presented. It is shown that when offset cancellation and dynamic element matching techniques are applied, the accuracy of the sensor is mainly limited by process spread between batches on the substrate bipolar transistors. Therefore, the sensors can be calibrated per batch instead of per sensor. In combination with a second-order curvature correction technique, this results in a three-sigma accuracy of ±1.5°C over the full temperature range