Noise susceptibility of ΔVBE temperature sensors in highly integrated power converters

This paper introduces the detrimental effects of voltage regulator noise on ΔV_BE-based temperature sense circuits. The work began when a significant temperature reporting inaccuracy was observed on a commercial DC-DC power conversion module. In the paper, the observed problem will be discussed, and a Spice model presented which allows the issue to be simulated. The main part of the work, however, concentrates on a comprehensive experimental investigation of the problem. Taking into account the findings of this investigation, it was possible to significantly improve the accuracy of ΔV_BE temperature sense circuits even when exposed to high levels of EMI. The paper concludes by offering important design guidelines for both analog and applications engineers when these high-precision temperature sense circuits are used on power conversion circuits.