Electrothermal effects in integrated circuits

Abstract

Thermal coupling among integrated circuit components is generally regarded as having a detrimental effect on circuit performance, particularly in power operational amplifiers, reference voltage circuits and voltage regulators. The design of such circuits must take into account these ‘electrothermal interactions’, as they are termed. However, for certain other circuit applications, it is possible to use these interactions to advantage. In this paper, thermal analysis methods for integrated circuits are described briefly, with emphasis on a computer simulation of electrothermal interactions. The exploitation of electrothermal interactions is discussed for temperature stabilisation of the integrated chip, for generation of long duration pulses, and for synthesis of low frequency (less than 100 Hz) filters. In the last case a state variable method is used, enabling the synthesis, with electrothermal integrators, of low pass, high pass, band pass, and band elimination filters. Experimental results are given, and limitations and applications are briefly discussed.