Marcin Janicki

Ion sensitive field effect transistor modelling for multidomain simulation purposes

Abstract The proper design and simulation of modern electronic microsystems oriented towards environment monitoring requires accurate models of various ambient sensors. In particular, this paper presents a comprehensive model of an ion sensitive field effect transistor (ISFET). The model can be employed straightforwardly for simulations at device, circuit or system level. First, the model was validated with electrical measurements and simulations of real structures performed for different ion concentration and temperature values. Then, the ISFET sensor model was employed for mixed-signal simulations in VHDL-AMS, when the analysis of a microsystem consisting of the ISFET sensor and a sigma–delta analogue-to-digital converter was carried out. Additionally, the presence of other ions than hydrogen in the measured solution was also taken into account in the simulations.

Thermal analysis of layered electronic circuits with Green's functions

This paper presents a method for thermal simulation of electronic circuits using an analytical solution of the three-dimensional heat equation resulting from an appropriate circuit thermal model. The temperature fields in multilayered structures are computed analytically employing the Greens functions solution method. The entire solution methodology is illustrated in detail on the particular examples of electronic circuits containing multiple heat sources. Compared to the previous papers published by the authors, the method has been extended by including the possibility of simulating imperfect layer contacts. The simulation results are validated with infra-red measurements and results obtained using other methods. Additionally, the discussion of simulation errors caused mainly by different non-linear phenomena is included.

Hot spots and core-to-core thermal coupling in future multi-core architectures

This paper studies hot spot and thermal coupling problems in future multicore architectures as CMOS technology scales from 65 nm feature size to 15 nm. We demonstrate that the thermal coupling between neighboring cores will dramatically increase as the technology scales to smaller feature sizes. The simulation studies were based on solving the heat equation using the analytical Greens function method. Our simulations indicate that the thermal coupling in the 15 nm feature size just after 100 ms of operation will increase from 20% to 42% and in the steady state might reach even 65%. This finding uncovers a major challenge for the design of future multi-core architectures as the technology keeps scaling down. This will require a holistic approach to the design of future multi-core architectures encompassing low power computing, thermal management technologies and workload distribution.

Transient thermal analysis of multilayered structures using Green's functions

Abstract This paper presents an approach to the analysis of transient thermal states in electronic circuits using an analytical solution of the heat equation. Fully three-dimensional analytical time dependent solutions are determined for multilayered structures with the help of Greens functions (GFs). The GFs required for the solution are found using a Galerkin-based integral method. The entire solution method is illustrated in detail using a practical example, where the results of transient thermal simulations of a real hybrid power module are compared with infrared measurements.

Automated stand for thermal characterization of electronic packages

This paper presents the design and the practical realization of a measurement stand dedicated to thermal characterization of electronic packages. The standard Dual Cold Plate (DCP) solution is enhanced with the Peltier Thermo-Electric Modules (TEMs) and a tensometer bridge. The TEMs are automatically controlled by a special circuit so as to provide either constant case temperature or constant thermal resistance to ambient. The tensometers are used to assure parallel alignment of the layers and to adjust contact thermal resistance between them. The realized stand is thoroughly tested and verified during the measurements of a power diode.

Application of Green's functions for analysis of transient thermal states in electronic circuits

This paper presents an approach to the modelling of transient thermal states in electronic circuits using an analytical solution of the heat equation. Fully three-dimensional analytical time dependent solutions are determined with the help of Greens functions. The solution method is illustrated in detail on a practical example, where the results of transient thermal simulations of a real hybrid circuit are compared with infrared measurements.

Generation of reduced dynamic thermal models of electronic systems from time constant spectra of transient temperature responses

This paper concerns the problem of generating reduced dynamic thermal models whose elements have physical interpretation. The compact models of an electronic system are generated here based on the analysis of the time constant spectra of system transient thermal responses. The proposed method is illustrated on a practical example of an integrated power amplifier with a heat sink. The experiments demonstrate the influence of contact resistance and cooling conditions on the resulting values of thermal model elements.

Modelling electronic circuit radiation cooling using analytical thermal model

Abstract This paper presents a thermal model of electronic circuit based on an analytical solution of the heat equation. In particular, the question of modelling circuit radiation cooling is discussed. The proposed model with temperature dependent heat exchange coefficient is applied for the analysis of an integrated circuit. Simulation results are validated with both infrared and p–n junction measurements.

Impact of nonlinearities on electronic device transient thermal responses

This paper investigates the influence of nonlinearities on electronic device thermal transient responses. The discussions in the paper are based on practical examples where thermal responses of a power device are recorded in various boundary conditions for different values of dissipated power. Then, the measurement results are analysed using the Network Identification by a Deconvolution method and the differences between particular cases are discussed in detail. The presented experimental results demonstrate that the nonlinearities due to the temperature dependence of thermal model parameters might have important influence on the results, especially when still air cooling is applied. In addition, in selected cases the simulations results obtained with compact thermal models were compared with measurements.

Behavioral Approach to SiC MPS Diode Electrothermal Model Generation

A comprehensive approach to generation of electrothermal models of silicon carbide (SiC) power Schottky diodes is presented. Both the electrical and thermal parts of the model are behavioral. The electrical one was developed in order to accurately represent the nonlinear properties of SiC merged PiN Schottky (MPS) diodes. Its parameters are automatically obtained with a dedicated numerical procedure. The thermal model derivation differs from the earlier approaches because it is based on the analysis of thermal constant spectrum of the temperature response of a modeled device. Simple model generation and parameter extraction procedures are proposed in which no knowledge of technological data is necessary.