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Ultrasound power delivery can be considered a convenient technique for charging implantable medical devices. In this work, an intra-body system has been modeled to characterize the phenomenon of ultrasound power transmission. The proposed system comprises a Langevin transducer as transmitter and an AlN-based square piezoelectric micro-machined ultrasonic transducer as receiver. The medium layers, in which elastic waves propagate, were made by polydimethylsiloxane to mimic human tissue and stainless steel to replace the case of the implantable device. To characterize the behavior of the transducers, measurements of impedance and phase, velocity and displacement, and acoustic pressure field were carried out in the experimental activity. Then, voltage and power output were measured to analyze the performance of the ultrasound power delivery system. For a root mean square voltage input of approximately 35 V, the power density resulted in 21.6 mu W cm(-2). Such a result corresponds to the data obtained with simulation through a one-dimensional lumped parameter transmission line model. The methodology proposed to develop the ultrasound power delivery (UPD) system, as well as the use of non-toxic materials for the fabrication of the intra-body elements, are a valid design approach to raise awareness of using wireless power transfer techniques for charging implantable devices. Web of Science 13 12 art. no. 2127

Chaotic systems, presenting complex and nonreproducible dynamics, may be found in nature, from the interaction between planets to the evolution of weather, but can also be tailored using current technologies for advanced signal processing. However, the realization of chaotic signal generators remains challenging due to the involved dynamics of the underlying physics. In this paper, we experimentally and numerically present a disruptive approach to generate a chaotic signal from a micromechanical resonator. This technique overcomes the long-established complexity of controlling the buckling in micro/nanomechanical structures by modulating either the amplitude or the frequency of the driving force applied to the resonator in the nonlinear regime. The experimental characteristic parameters of the chaotic regime, namely, the Poincaré sections and Lyapunov exponents, are directly comparable to simulations for different configurations. These results confirm that this dynamical approach is transposable to any kind of micro/nanomechanical resonator, from accelerometers to microphones. We demonstrate a direct application exploiting the mixing properties of the chaotic regime by transforming an off-the-shelf microdiaphragm into a true random number generator conforming to the National Institute of Standards and Technology specifications. The versatility of this original method opens new paths to combine the unique properties of chaos with the exceptional sensitivity of microstructures, leading to emergent microsystems.

This paper presents analytic and numerical modelling of a MEMS electrodynamic micro-sensor of dynamic pressure. Two coaxial planar inductors of different diameters are used in the proposed micro-sensor design. Using finite element analysis, the diaphragm resonant frequency and dynamic displacements are evaluated for different diaphragm thicknesses. Then, the total sensitivity is deduced by coupling different physical domains which contribute in the micro-sensor operation. A lumped element model is built in order to study the micro-sensor sensitivity and define the dynamic performance for different resonant frequencies. This model shows that the best sensitivity, within the mV/Pa range, is obtained around the resonant frequency when operation in the audible frequency range, and decreases to the uV/Pa range for ultrasonic frequencies. The obtained sensitivity curves prove that the undamped inductive micro-sensor can offer high pressure sensitivity within a narrow frequency bandwidth.

The paper presents a technique to obtain an electrically-tunable matching between the series and parallel resonant frequencies of a piezoelectric MEMS acoustic transducer to increase the effectiveness of acoustic emission/detection in voltage-mode driving and sensing. The piezoelectric MEMS transducer has been fabricated using the PiezoMUMPs technology, and it operates in a plate flexural mode exploiting a 6 mm × 6 mm doped silicon diaphragm with an aluminum nitride (AlN) piezoelectric layer deposited on top. The piezoelectric layer can be actuated by means of electrodes placed at the edges of the diaphragm above the AlN film. By applying an adjustable bias voltage Vb between two properly-connected electrodes and the doped silicon, the d31 mode in the AlN film has been exploited to electrically induce a planar static compressive or tensile stress in the diaphragm, depending on the sign of Vb, thus shifting its resonant frequency. The working principle has been first validated through an eigenfrequency analysis with an electrically induced prestress by means of 3D finite element modelling in COMSOL Multiphysics®. The first flexural mode of the unstressed diaphragm results at around 5.1 kHz. Then, the piezoelectric MEMS transducer has been experimentally tested in both receiver and transmitter modes. Experimental results have shown that the resonance can be electrically tuned in the range Vb = ±8 V with estimated tuning sensitivities of 8.7 ± 0.5 Hz/V and 7.8 ± 0.9 Hz/V in transmitter and receiver modes, respectively. A matching of the series and parallel resonant frequencies has been experimentally demonstrated in voltage-mode driving and sensing by applying Vb = 0 in transmission and Vb = −1.9 V in receiving, respectively, thereby obtaining the optimal acoustic emission and detection effectiveness at the same operating frequency.

We report on a piezoelectric micromachined ultrasonic transducer (PMUT) driven in a nonlinear regime, generating chaotic amplitude modulated ultrasonic waves. At large enough drives, the PMUT enters in the Duffing regime which opens a hysteresis with two available states. By modulating the frequency of the driving signal, the system may switch between both states, and selecting the appropriate modulation frequency enables to enter in the chaotic regime. The chaos is then imprinted as a modulation of the PMUT’s amplitude. We characterize this regime in the three accessible domains: electrical, mechanical and acoustic, and demonstrate they are fully correlated. We then focus on the generated acoustic signals and demonstrate that the chaotic modulation propagates according to the PMUT’s linear regime. Remarkably, the detected acoustic waves are strongly correlated to the on-chip piezoelectric measurements, regardless of the acoustic beam profile. The frequency spectrum of the chaotic modulation spreads around the ultrasonic carrier, mimicking a noise modulated carrier signal. We exploit this property for jamming applications where the chaotic PMUT is used to mask surrounding acoustic waves. Unlike most jamming applications, our approach does not require driving signals with a broad frequency spectrum, the noisy pattern arising directly from the structure’s dynamics. Using two PMUTs, one in the linear and the other in the nonlinear regime, we realize a proof-of-concept where the ultrasound generated by the first PMUT is drowned out by the chaotic PMUT signal. We demonstrate that the carrier frequency of the jamming PMUT does not need to match perfectly the one of the linear PMUT. This chaos generation is generic and could be adapted to any PMUT, and thanks to the rich frequency spectrum of the chaotic modulation, the frequency of the signal to jam does not need to be precisely known.

This article aims at providing a better behavior understanding and performance evaluation of a large-size passive on-chip tapped transformer when used as a transducer in low-frequency integrated microsystems [30–300 kHz]. Thus, a CMOS-based 1:1 transformer, consisting of 70 turns of 1.6- $\mu \text{m}$ -wide top-level metal spaced by 0.6 $\mu \text{m}$ and with a total length of 1.7 mm, has been investigated and tested. The spatial separation between the two transformer windings was set to 70 $\mu \text{m}$ . An electrical equivalent lumped model has been extracted through an exhaustive specific measurement procedure. The model is useful to simulate and evaluate the voltage transformation ratio (TR) between the two transformer windings. The effects of parasitics and imperfect coupling between transformer windings and through the silicon substrate are outlined from the circuit point of view. We report a magnetic coupling coefficient that does not exceed $k=0.15$ , with a voltage TR of about 0.39 around the resonance frequency of ~5.3 MHz, when the secondary is unloaded. It has been proven that the interwindings capacitance introduced by close conductors of each winding, evaluated to 13 pF, assures the most important role in the power transfer. This article has shown that by optimizing properly the transformer realization and limiting some parasitics elements, the inductive and capacitive links could both play a key role in MEMS transducers through tapped transformers operation around 100-kHz frequencies.

International audience; In this paper, a pioneer partial discharge (PD) loop antenna sensor is presented and examined. It is made of a 70-turn square planar inductor with a side length of 1.8mm, which is fabricated on top of a silicon substrate in complementary metal oxide semiconductor technology. The microsensor ability to detect corona PD is demonstrated once connected in series with a 60 dB gain amplifier. The behavior is studied at different separation distances from the line through which the PD pulses flow. At 5cm away, a damped sinusoidal induced voltage with an amplitude of about 100 mV has been measured. The output signal spectrum is highly concentrated around a central resonance frequency of ∼5MHz. The microsensor response is compared with those of other industrial sensors from Techimp, i.e., horn antennas and high-frequency current transformer sensors. The presented on-chip sensor can be considered a non-intrusive competing solution compared with other heavy and expensive commercial sensors due to its lightweight, compact size, and low cost. In addition, it shows an acceptable signal to noise ratio compared with other commercial electromagnetic wave-based sensors.

This work demonstrates the feasibility of an ultrasonic rangefinder with a sensing range of up to 1.5m based on a single piezoelectric micromachined ultrasonic transducer (PMUT) fabricated using a multi-user MEMS process (MUMPs). The dual-electrode design presented herein has been used to isolate the transmit (TX) and received (RX) paths within a single PMUT, thereby avoiding issues of frequency mismatch that is common to dual-PMUT designs. The reported ultrasonic rangefinder has a minimum detection limit of 0.3m.

International audience; A Piezoelectric Micro Electro-Mechanical System (Piezo-MEMS) acoustic transducer able to electrically tune the resonant frequency in receiver and transmitter modes is reported. The proposed 6×6mm squared diaphragm has been simulated by a 2D finite element model, fabricated, and measured. A DC bias voltage applied to the piezoelectric layer produces a controllable stress, thus leading to a matching of the series and parallel resonant frequencies. This allows to increase performances when the transducer is operated as both transmitter and receiver. The resonance can be tuned in a range of ±70 Hz by a DC voltage of ±8 V with an estimated sensitivity of 8.87 Hz/V.

International audience; This work presents a MEMS device with Aluminum Nitride (AlN) piezoelectric actuators on a silicon suspended plate developed for driving mechanical vortexes in aqueous solution, and hence obtain centrifugation of fluids. Innovatively, the MEMS device has the capability to force ClockWise (CW) or CounterClockWise (CCW) rotations of a fluid drop placed in contact with the MEMS suspended plate. Experimental results show that CW and CCW rotations have been obtained using a 2-mm-diameter drop of water.This capability advantageously could allow the use of the proposed MEMS device for applications where drop centrifugation with different rotation directions can change the chemical or biological properties of the fluids.

Micro-electro-mechanical systems (MEMS) allowed miniature microphones that during the last few decades have left research laboratories to enter a massive industrial development. Their characteristics meet the most demanding specifications of various portable devices. This talk will show some non-standard approaches to the fabrication technology and associated modeling issues using two cases of specific designs in support. The first case is a piezoresistive microphone devoted to high-intensity and high-frequency acoustic fields. To damp the resonance, an atypical diaphragm structure was employed. Such a solution, allowing relatively large airgap required by large diaphragm displacements, will be presented and analyzed. The second case concerns a design of a microphone fabricated with a standard complementary metal oxide semiconductor (CMOS) technology. This technology, in contrast with dedicated technologies typically used by the microphone industry, is readily available to small companies and academic institutions. One of the drawbacks of the CMOS-MEMS approach is a relatively high degree of design constraints represented by materials and layers dimensions involved in the CMOS process. Moreover, the device layout must take into account specific requirements of the fabrication technique. This talk will present some of these constraints and their impact on the microphone performance that will be supported by simulation results.Micro-electro-mechanical systems (MEMS) allowed miniature microphones that during the last few decades have left research laboratories to enter a massive industrial development. Their characteristics meet the most demanding specifications of various portable devices. This talk will show some non-standard approaches to the fabrication technology and associated modeling issues using two cases of specific designs in support. The first case is a piezoresistive microphone devoted to high-intensity and high-frequency acoustic fields. To damp the resonance, an atypical diaphragm structure was employed. Such a solution, allowing relatively large airgap required by large diaphragm displacements, will be presented and analyzed. The second case concerns a design of a microphone fabricated with a standard complementary metal oxide semiconductor (CMOS) technology. This technology, in contrast with dedicated technologies typically used by the microphone industry, is readily available to small companies and academic ins...

This paper addresses the development and characterization of a non-intrusive silicon-based microsensor, which can detect electric partial discharges in electrical insulation equipment. Early partial discharge detection prevents failures and can be used to optimize maintenance operations. Despite the potential that CMOS technology offers, miniaturized electric discharge detector has neither been investigated nor implemented, until now. The developed microsensor demonstrates its ability to record electric discharge emission thanks to the presence of a miniaturized planar inductor. The squared inductor of 50 turns with a side length of 1.5 mm used in our sensor has been fabricated on top of a silicon substrate in a CMOS technology. The total inductor wire length of loop antenna is 30 cm to achieve 100 MHz bandwidth. Using the microsensor at 1 cm from the discharge site, a damped sinusoidal induced voltage with an amplitude of 2 V has been measured at its output. We observed that the output signal spectrum is highly concentrated around a central resonance frequency, which remains constant. The main advantage of such design resides in its monolithic integration added to the high autonomy, which improves the microsensor efficiency.

We report on a micro-acoustic source based on industrial 0.35 μm CMOS-MEMS process with only one additional post-process step. The fabrication flow completed with the characterization results of an electrostatic micro-acoustic source based on 0.35 μm CMOS process with sacrificial SiO 2 etch is shown here for the first time. The acoustic pressure in air in the vicinity of the resonant frequency ( 32,2 kHz ) at the distance of 10 mm from the source was measured. The acoustic pressure of 12 mPa was obtained when the source was driven by AC signal of 6 V p-p and the DC bias of 8 V .

International audience; Micro Electro-Mechanical Systems (MEMS), applied to the field of hearing aids, offer ample possibilities for improving of performance, reliability and functional specifications, and they are also promising in terms of energy saving. In this paper, some of the major design problems relating to the use of MEMS for sound waves generation inside the ear canal are analyzed.

In this paper, we present the theoretical model validation of an integrated planar transformer used in MEMS electrodynamic microsensor. The structure consists of two planar inductors: an outer fixed one and an inner suspended one. If the outer inductor is biased by an AC voltage, a mutual inductance link will be created between both inductors. We present an analytical approach to determine the induced voltage when applying an AC supply current to the outer inductor. In the paper, we discuss the difference between the analytical results with and the characterization. The difference is basically due to the coupling capacitance between the inner and the outer inductors and not only, as we expected, due to the mutual inductance. The introduction of the coupling capacitance, estimated to be around 1.7pF, to our simulation confirmed the measurement performed on the planar integrated transformer.

International audience; This work presents a lumped parameters equivalent model of condenser microphone based on analogiesbetween acoustic, mechanical, fluidic, and electrical domains. Parameters of the model weredetermined mainly through analytical relations and/or finite element method (FEM) simulations.Special attention was paid to the air gap modeling and to the use of proper boundary condition.Corresponding lumped-parameters were obtained as results of FEM simulations. Because of itssimplicity, the model allows a fast simulation and is readily usable for microphone design. Thiswork shows the validation of the equivalent circuit on three real cases of capacitive microphones,including both traditional and Micro-Electro-Mechanical Systems structures. In all cases, it hasbeen demonstrated that the sensitivity and other related data obtained from the equivalent circuitare in very good agreement with available measurement data.

International audience; Silicon-based microphones are nowadays well-established MEMS components produced by strong industrial actors.The fabrication of such acoustic sensors is based on a dedicated technology fulfilling all designed parameters. On the other hand, the development of such a technology processes is costly and time-consuming. In this paper, we will present approaches based on technologies readily available to small companies and academic institutions. We will show, on several examples, a design process of acoustic micro-transducers fabricated through generic technologies. Focused will be a CMOS-MEMS process applied to therealization of suspended diaphragms that can be part of transducers with piezoresistive, electrostatic, or electrodynamic transduction. We will also briefly present a testing technique that can be used for acoustic sensors calibration. This technique has a special interest for sensors with a frequency response exceeding the typical audible range.

International audience; This paper presents an improved design of the electrodynamic CMOS-MEMS microphone. The studied microphone is based on two integrated concentric planar inductors, a fixed outer one and an inner one attached on a flexible vibrating diaphragm. First, the magnetic field, generated by the outerinductor, was evaluated. Unlike conventional electrodynamic microphones based on Faraday’s law, the induced voltage was found to be proportional to the product of the diaphragmdisplacement and its velocity. Even though the induced output voltage is in the range of a few microvolts, and its frequency is doubled compared to that of the incident acoustic wave. Thisresult pushed us to adjust and improve the basic principle of this kind of microphone by trying to generate a vertical downward shift of the microphone diaphragm while maintaining the COMScompatibility. The Lorentz force appears to be a possible alternative to the wafer bonding, as it will be automatically generated when we bias the inner inductor by a dc current. First, this paper shows that the induced voltage will be linear for a vertical fluctuation magnitude lower than 10 μm with an induced voltage in the range of several microvolts. Using the developed vertical offset technique, we show that induced voltages can be increased by a factor of 10 and the dynamic response of the electrodynamic microsensor will be appropriate for a use as a microphone.

International audience; Micro-structured cellular polydimethylsiloxane (PDMS) materials were prepared by a low-cost molding process allowing us to control geometry and sample size. Cellular structures are charged with a triangular quasi-static voltage with amplitudes between 1 kV and 4 kV and a frequency of 0.5 Hz fixed after having evaluated the conditions enhancing the piezoelectric response of the cellular PDMS. The piezo-electret PDMS material charged at room temperature has a piezoelectric coefficient d 33 of 350 pC/N, which is ten times larger than that of polyvinylidene fluoride. The high piezoelectric coefficient with a very low elastic modulus of 300 kPa makes these materials very useful for wearable device applications. The piezoelectric coefficient d 33 of the samples poled at high temperatures improves thermal stability but reduces PDMS piezo-electret piezoelectricity, which is explained by the structure's stiffness. These results are useful and allow us to set the conditions for the preparation of the piezo-electret materials according to desired applications.

International audience; We report on a micro-acoustic source based on industrial 0.35 μm CMOS-MEMS process with only one additional post-process step. The fabrication flow completed with the characterization results of an electrostatic micro-acoustic source based on 0.35 μm CMOS process with sacrificial SiO2 etch is shown here for the first time. The acoustic pressure in air in the vicinity of the resonant frequency (32 kHz) at the distance of 10 mm from the source was measured. The acoustic pressure of 12 mPa was obtained when the source was driven by an AC signal of 6 VAC and a DC bias of 8 VDC.

International audience; A surface acoustic wave (SAW) device is used in this work as the sensing element for a chemical sensor that will be embedded in a wireless sensor node. The SAW device is intended to detect the concentration of gaseous mercury in the environment. The microelectronics front-end architecture has been designed at transistor level in a CMOS technology. The SAW device is embedded in a phase-locked loop (PLL) that converts the change of concentration of gaseous mercury into a shift of the loop frequency. Post-layout simulations of the overall sensor including the digital control and read-out blocks have been carried out considering a model of the SAW device described in the Hardware Description Language Verilog-A. Analog tests on the fabricated circuit have demonstrated the functionality of this microelectronics front-end interface.

International audience; In the context of the scientific program SIMMIC supported by the French National Agency for Research (SIMI 9, ANR 2010 BLANC 0905 03), new wide band MEMS piezoresistive microphones have been designed and fabricated for weak shock wave measurements. The fabricated microphones have a high frequency resonance between 300 to 800 kHz depending on the membrane size. In order to characterize the frequency response of the fabricated sensors up to 1 MHz, new calibration methods based on an N-wave source were designed and tested. Short duration spherical N-waves can be generated by an electric spark source. To estimated a constant sensitivity coefficient, a known method is based on the estimation of the peak pressure from the lengthening of N-waves induced by non linear propagation. However, to obtain the sensitivity as a function of frequency, the output voltage must be compared to the incident pressure waveform, which must be accurately characterized. Taking advantage of recent works on the characterization of pressure N-waves generated by an electric spark source by means of optical methods, two calibration methods have been designed to obtain the frequency response. A method based on the comparison with pressure waveforms deduced from the analysis of schlieren images allowed to estimate the frequency response. A second method, based on a Mach-Zender optical interferometer, was found to be the best method to estimate the sensitivity of microphones up to 1 MHz. The methods were first tested by calibrating standard 1/8 inch condenser microphones. Then, frequency responses of different MEMS microphones prototypes were characterized to test different sensor designs. Results show that using a spark source and optical methods it is possible to calibrate sensors in the frequency range 10 kHz-1 MHz. The new calibration methods were used to improve the design of new high frequency MEMS pressure sensors.

International audience; The electro-mechanical characterization of MEMS diaphragms for acoustic applications is introduced in this paper. The samples under test are fabricated with the 0.35 AMS CMOS process with front-side surface etching post-process. The goals of the experimental activities are to verify the performances and repeatability of fabrication process and to identify the static and dynamic properties of diaphragms in comparison to the predictions of FEM models. In order to verify the applicability of this kind of devices to acoustic applications, the pressure generation in air has been measured with a measuring microphone with appreciable results.

International audience; Electro-active polymers are emerging in the fields of actuators and micro-sensors because their good dielectric and mechanical properties makes them suitable for such applications. In this work, we focus on micro-structured (cellular) polymer materials (referred as piezoelectrets or ferroelectrets) that need prior charging to attain piezoelectric behaviour. The development of such applications requires an in-depth knowledge of the intrinsic dielectric properties of such structures and models to enable the accurate prediction of a given micro-structured material’s dielectric properties. Various polymers including polypropylene, polytetrafluoroethylene, fluoroethylenepropylene, cyclo-olefines and poly(ethylene terephthalate) in a cellular form have been studied by researchers over the last fifteen years. However, there is still a lack of information on the intrinsic dielectric properties of the most recently used dielectric polymer (polydimethylsiloxane, PDMS) over wide frequency and temperature ranges. In this work, we shall propose an exhaustive equivalent electrical circuit model and explain how it can be used to predict the micro-structured PDMS complex permittivity versus frequency and temperature. The results obtained from the model were found to be in good agreement with experimental data for various micro-structured PDMS materials. Typically, for micro-sensor applications, the dielectric constant and dielectric losses are key factors which need to be minimized. We have developed a configuration which enables both to be strongly reduced with a reduction of 16% in the dielectric constant of a micro-structured PDMS compared with the bulk material. In addition, the phenomena responsible for dielectric losses variations with frequency and temperature are discussed and correlated with the theoretical model. Our model is thus proved to be a powerful tool for the control of the dielectric properties of micro-structured PDMS material for micro-sensor applications.

This paper gives a detailed electroacoustic study of a new generation of monolithic CMOS micromachined electrodynamic microphone, made with standard CMOS technology. The monolithic integration of the mechanical sensor with the electronics using a standard CMOS process is respected in the design, which presents the advantage of being inexpensive while having satisfactory performance. The MEMS microphone structure consists mainly of two planar inductors which occupy separate regions on substrate. One inductor is fixed; the other can exercise out-off plane movement. Firstly, we detail the process flow, which is used to fabricate our monolithic microphone. Subsequently, using the analogy between the three different physical domains, a detailed electro-mechanical-acoustic analogical analysis has been performed in order to model both frequency response and sensitivity of the microphone. Finally, we show that the theoretical microphone sensitivity is maximal for a constant vertical position of the diaphragm relative to the substrate, which means the distance between the outer and the inner inductor. The pressure sensitivity, which is found to be of the order of a few tens of μV/Pa, is flat within a bandwidth from 50 Hz to 5 kHz.

International audience; In the context of both nonlinear acoustics, and downscaled acoustic or aero-acoustic experiments, thecharacterization of the high frequency response of microphones and pressure sensors remains acritical challenge. In the case of the design of new MEMS microphones and shock pressure sensorswith response in the frequency range of 10 kHz–1 MHz, this question was addressed by the definitionof a new calibration method based on a spark source that generates spherical weak shock acousticpulse. Waves are short duration non-symmetric N-waves with duration of about 40 microseconds andfront shock rise time of the order of 0.1 microsecond. Taking advantage of recent works on thecharacterization of such pressure waves using an optical interferometer, and considering non linearpropagation of weak shockwaves, we were able to estimate the incident pressure wave in the rangeof 10 kHz–1MHz. Hence, from the output voltage of the microphones, the frequency response wasobtained in this range. The method applies whatever the transduction principle and the sensormounting. [Work supported by the French National Agency for Research (SIMI 9, ANR 2010 BLANC0905 03, and LabEx CeLyA ANR-10-LABX-60/ANR-11-IDEX-0007).]

As predicted by technology roadmaps, embedded micro-electro-mechanical-systems (MEMS) is yet another step in the continuous search for higher levels of integration and miniaturization. MEMS are analog components and the test paradigm is similar to the case of analog and mixed-signal circuits. However, given the fact that they work with signals other than electrical, the test of these embedded parts poses new challenges. In this paper, we will review some recent works in this field and we will present a complete approach to MEMS built-in-self-test (BIST) based on pseudorandom testing.

Invited Talk; International audience; This paper is aimed at exploiting Fault Detection and Isolation (FDI) techniques widely known in automatic control for solving online test problem in embedded Integrated Circuits (ICs). Before reaching this aim, we will briefly review the field of microelectronics testing, introducing basic concepts and techniques. We will next introduce FDI model-based approaches and their application for online testing of embedded ICs considering linear systems with potential faults and disturbances. The parity relation-based residual is specially suitable for this type of application. As an example, we will apply it to concurrent fault detection in a digital embedded filter. The proposed scheme will then be illustrated for a linear digital pass-band elliptic filter.

With the rapid development of system-on-chip (SoC) applications, containing digital and analogue parts, the need for fast and reliable on-chip testing methods has become obvious. We present a method for a fast and accurate broadband determination of the behaviour of analogue and mixed-signal circuits. This technique is based on impulse response (IR) evaluation using pseudo-random Maximum-Length Sequences (MLS). This approach provides a large dynamic range and is thus an optimal solution for measurements in noisy environments and for low-power test signals. We will show the algorithms of the MLS generation and of the impulse response calculation which can be easily implemented on-chip.

International audience; With the mechanical resonance damped using a perforated back-plate underneath the sensing diaphragm, a piezoresistive aero-acoustic microphone with improved high-frequency characteristics is demonstrated. The sensing diaphragm and the damper back-plate were monolithically integrated in one process flow. The microphone was calibrated using a high-voltage electrical spark-discharge acoustic N-wave source. A sensitivity of ~0.33 μV/V/Pa, a bandwidth of ~520 kHz at 3-dB attenuation, and a significant damping of the mechanical resonance were realized.