Automatic generation of electro-thermal models with TRAPPIST

It has been shown that the transfer function trajectories (TFT) approach allows the automated extraction of compact behavioral models for analog and mixed-signal circuit blocks. The models consist in the concatenation of a multiple-input-multiple-output (MIMO) linear filtering stage and a nonlinear scheduling stage, ensuring a very broad coverage for the method. Models that are generated with the TRAPPIST method (TRajectory Approximation by the Identification of State-dependent Transfer functions) were shown capable of achieving adjustable error versus complexity trade-offs to reproduce the response of any arbitrary realization and to account for voltage variations and stochastical design parameters. In this paper, the TRAPPIST method is used to create an electro-thermal behavioral model of the circuit, by merging data from a (pure) thermal simulator and from standard iso-thermal circuit simulations. The resulting TFT model has an error below 2% and allows to alter the temperature dynamically during time-domain simulations.