Analysis of the residual error due to mechanical stress in BJT-based CMOS temperature sensors

Abstract

It is widely known that the inaccuracy of BJT-based CMOS temperature sensors is higher at high temperature range, which greatly limits their application. In this paper, the characteristic of the error after calibration is analyzed. Through the experiments, we discover that the cause of this problem is not circuit related, instead it is process related, which is the mechanical stress generated during manufacturing and packaging. Experimental results show that an accuracy of −0.5 ~ 2 °C can be obtained for the calibrated non-epoxy sensors from −40 °C to 120 °C.