A methodology to extract dynamic compact thermal models under time-varying boundary conditions: application to a thermopile based IR sensor

Abstract

This paper presents the extraction of a boundary independent dynamic compact thermal model (DCTM). The paper specifically focuses on time-varying Dirichlet boundary conditions influence and the methodology proposed to obtain the DCTM is applied to a thermopile based infrared (IR) sensor. These type of sensors are quite sensitive to environment changes because a variation in the sensor bulk silicon temperature usually generates a different temperature influence in the hot and cold areas that can produce incorrect transient measurements of the incident IR radiation. A DCTM can be used to estimate the influence of the environmental temperature evolution in the sensor output and with the help of a temperature sensor correct the measurement of the IR incident radiation in the real device. The methodology to construct the DCTM is based in the construction of an equivalent thermal RC network, the topology of which, as well as its component values, are obtained from the analysis of the dynamic power-temperature relationship on the points of interest.