Geneviève Duchamp

Electromagnetic immunity model of an ADC for microcontroller’s reliability improvement

This paper deals with the study of electromagnetic compatibility prediction of integrated circuits in order to improve their reliability. The study takes place in the context of embedded electronic circuit where the proximity of the analog and digital parts increases. The case of microcontroller is considered and more particularly the susceptibility of the Analog to Digital Converter (ADC) device. The use of the new immunity approach (ICIM-CI model) is proposed to achieve the susceptibility modelling of the ADC. The model is built step by step (functional and coupling path models). Then, it is possible to estimate the effect of disturbances on the sensitive nodes. Finally the aim of EMC circuit compliance is enhanced.

An alternative method for end-effect characterization in shorted slotlines

In this paper, we propose an alternative method to characterize the end effects in shorted slotlines. Using a commercial software to model the transition, a simple mathematical expression of the end impedance, valid for a given substrate family and in a wide frequency domain, was achieved. Several dielectric substrates were considered and the obtained results were compared with experimental ones. A correct agreement was observed. This approach can also be useful in more complex simulations relative to multilayer structures.

Control of the electromagnetic compatibility: An issue for IC reliability

Abstract This paper deals with the use of two main standard modeling approaches in order to control the electromagnetic compatibility of an IC before manufacturing. An application is given in the case of a complex mixed circuit which is an Analog to Digital Converter (ADC) embedded in a microcontroller. The digital core (DC) of the microcontroller consumes dynamic currents which generate internal disturbances and, as a consequence, a loss of the ADC accuracy is observed. At first, the conducted emission of the DC is estimated by using the ICEM-CE model. Then, the ADC immunity is modeled with ICIM-CI methodology. Based on these two models, a simulation at the chip level is performed to estimate the loss of accuracy of this ADC. Finally, this study is the first step in the development of a methodology for virtual prototyping allowing, from the design, the evaluation of the integrated circuit sensitivity to electromagnetic interference in order to improve its reliability.

Characterization and model of temperature effect on the conducted immunity of Op. Amp

Abstract This paper deals with the study and the modelling of temperature effects on conducted immunity of electronic circuits. We focus first on experimental measurements using DPI (direct power injection) test bench for the characterization of conducted immunity associated to an air conditioner that allows warming up the circuit locally. It is shown that the increase of temperature seems to decrease the sensibility of the tested circuit. Secondly the behavioural immunity model (ICIM-CI), developed in VHDL-AMS and taking into account temperature effects is presented. The model is finally validated by comparison with measurements.

A methodologic project to characterize and model COTS components EMC behavior after ageing

The industries of transportation as the space industry are faced with a strong global economic competition which sets economic constraints on the cost of the functions. The use of COTS (Commercial Off-The-Shelf) components in embedded systems is more and more necessary to shorten the development cycles and reduce manufacturing costs. The application of electronic components comes overwhelmingly from public sectors whose requirement is to provide, in short development cycles, technological innovations including risk and cost mitigation. These development cycles must incorporate the specific constraints of embedded systems which are subject to strong normative requirements in terms of robustness and especially in terms of ElectroMagnetic Compatibility (EMC). In order to anticipate the risk of EMC non-compliance at electronic equipment level, the use of simulation tools and the development of EMC components models particularly at Integrated Circuits level has grown in recent years.

A methodological approach for predictive reliability: Practical case studies

Abstract The paper first describes challenges that engineers face in predicting the reliability of microelectronic assemblies. In addition, the constraints such as temperature, temperature cycle or moisture may interact with each other. So it is not feasible to solve the reliability problems without a methodological approach. The paper presents also case studies to illustrate a methodology combining experiments and simulations.

Near-field EMC study to improve electronic component reliability

This paper deals with the study of near-field electromagnetic compatibility (EMC) characterisation of electronic devices in order to improve their reliability in the context of the embedded electronic systems where the proximity of RF blocks and digital parts on the same circuits or in the same package increases. Such juxtaposition can lead to more important electromagnetic interferences inducing functional failures and the knowledge of EM behaviour of electronics becomes necessary. After a brief theoretical approach description, the experimental study is detailed. Simulations and measurements are performed and evidence the frequency range of device susceptibility.

A new tool for slot-microstrip transition simulation

We present the specific modelization with the MDS software and its MOMENTUM module, the technology brought into operation, and the obtained measurements for different structures involving the slot-microstrip transition. The experimental results are compared to those achieved by simulation. These works, as a whole, make it possible to evidence the interest of such a topology and the advantages of its simulation.

Qualification procedure for moisture in embedded capacitors

Abstract Embedding passives in PCB permits to gain in integration density while enhancing electromagnetic compatibility performances. The choice of the dielectric film is fundamental for large frequency band stability of embedded capacitances. However, these materials are prone to water absorption, which can lead to functional parameter degradations and additional stresses at the interfaces. This paper presents experimental capacitors embedded in FR-4, and finite element simulations of moisture absorption in various dielectric materials. Technological choices, as well as the qualification procedure, can be improved thanks to the simulation results.

Simulation of aging effects on radiated emission of microstrip line

This paper deals with the influence of humidity and temperature stresses on a microstrip line. These aging factors induce degradation on the dielectric and geometric properties. So the aim of this study is the evaluation of the influence of such variations on the radiated emission of a microstrip line using electromagnetic simulator. Due to the difficulty to interpret and analyze the results because of the correlation between the parameters, we have established a Design Of Experiments (DOE) to optimize the simulation procedure. The result coupled to ANOVA method gives better knowledge on the influences factors. The studys conclusions lead to simplify the experiments tests.