Test and Reliability of Electronic Circuits in Natural and Radiative Environment

There is a single and continuous line that links my learning career, scientific activities, teaching activities, projects and collaborations. At the beginning of my research career, the skills accumulated with the studies in microelectronics were applied to memory test. Next, this experience allowed making a further step towards the researches on diagnostic, reliability, power-aware test and low power circuits. At this point, I was ready to start my researches in a neighboring science field: radiation and spatial studies. This latest activity is growing a lot in my works and it is strongly combined with my initial interests. My research perspectives are linked with the ongoing works and projects on testing, spatial and radiation fields

A Model-Based Framework to Assess the Reliability of Safety-Critical Applications

Solutions based on artificial intelligence and brain-inspired computations like Artificial Neural Networks (ANNs) are suited to deal with the growing computational complexity required by state-of-the-art electronic devices. Many applications that are being deployed using these computational models are considered safety-critical (e.g., self-driving cars), producing a pressing need to evaluate their reliability. Besides, state-of-the-art ANNs require significant memory resources to store their parameters (e.g., weights, activation values), which goes outside the possibility of many resource-constrained embedded systems. In this light, Approximate Computing (AxC) has become a significant field of research to improve memory footprint, speed, and energy consumption in embedded and high-performance systems. The use of AxC can significantly reduce the cost of ANN implementations, but it may also reduce the inherent resiliency of this kind of application. On this scope, reliability assessments are carried out by performing fault injection test campaigns. The intent of the paper is to propose a framework that, relying on the results of radiation tests in Commercial-Off-The-Shelf (COTS) devices, is able to assess the reliability of a given application. To this end, a set of different radiation-induced errors in COTS memories is presented. Upon these, specific fault models are extracted to drive emulation-based fault injections

Use of CCD to Detect Terrestrial Cosmic Rays at Ground Level: Altitude vs. Underground Experiments, Modeling and Numerical Monte Carlo Simulation

International audienceIn this work, we used a commercial charge-coupled device (CCD) camera to detect and monitor terrestrial cosmic rays at ground level. Multi-site characterization has been performed at sea level (Marseille), underground (Modane Underground Laboratory) and at mountain altitude (Aiguille du Midi-Chamonix Mont-Blanc at +3,780 m of altitude) to separate the atmospheric and alpha particle emitter's contributions in the CCD response. An additional experiment at avionics altitude during a long-haul flight has been also conducted. Experiment results demonstrate the importance of the alpha contamination in the CCD response at ground level and its sensitivity to charged particles. Experimental data as a function of CCD orientation also suggests an anisotropy of the particle flux for which the device is sensitive. A complete computational modeling of the CCD imager has been conducted, based on a simplified 3D CCD architecture deduced from a reverse engineering study using electron microscopy and physico-chemical analysis. Monte Carlo simulations evidence the major contribution of low energy (below a few MeV) protons and muons in the CCD response. Comparison between experiments and simulation shows a good agreement at ground level, fully validated at avionics altitudes with a much higher particle flux and a different particle cocktail composition

The large area detector onboard the eXTP mission

The Large Area Detector (LAD) is the high-throughput, spectral-timing instrument onboard the eXTP mission, a flagship mission of the Chinese Academy of Sciences and the China National Space Administration, with a large European participation coordinated by Italy and Spain. The eXTP mission is currently performing its phase B study, with a target launch at the end-2027. The eXTP scientific payload includes four instruments (SFA, PFA, LAD and WFM) offering unprecedented simultaneous wide-band X-ray timing and polarimetry sensitivity. The LAD instrument is based on the design originally proposed for the LOFT mission. It envisages a deployed 3.2 m2 effective area in the 2-30 keV energy range, achieved through the technology of the large-area Silicon Drift Detectors - offering a spectral resolution of up to 200 eV FWHM at 6 keV - and of capillary plate collimators - limiting the field of view to about 1 degree. In this paper we will provide an overview of the LAD instrument design, its current status of development and anticipated performance

Leakage Read Fault in Nanoscale SRAM: Analysis, Test and Diagnosis

In this paper we study the impact of leakage currents on the operation of SRAM memories fabricated using nanoscale technologies. We show how the leakage currents, flowing through the pass transistors of unselected cells, may affect the read operation causing Leakage Read Faults (LRFs). The results of extensive Spice simulation on a 65nm SRAM are analyzed to evaluate the occurrence of the LRF for different operating conditions including supply voltage, temperature and frequency. Furthermore, the test requirements to cover LRFs are given and a low complexity (?2N) March test is proposed for diagnostic purposes

Reducing Power Dissipation in SRAM during Test

In this paper we analyze the power consumption of SRAM memories and demonstrate that the full functional pre-charge activity is not necessary during test because of the predictable addressing sequence. We exploit this observation in order to minimize power dissipation during test by eliminating the unnecessary power consumption associated with the pre-charge activity. This is achieved through a modified pre-charge control circuitry, exploiting the first degree of freedom of March tests, which permits to choose a specific addressing sequence. Further, the modified pre-charge logic allows also the switching between the normal functional mode and the low power test mode. We demonstrate that the modified pre-charge control circuitry has little or no effect on the memory performance. We analyze the sources of power consumption in functional and low power test mode, and we show how the power dissipation is computed for bit and word-oriented SRAMs. The efficiency of the proposed solution is validated through extensive Spice simulations for both bit-oriented and word-oriented SRAM

TA02-13: TOSHE - Test Of Systems for Harsh Environment

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Test of 90nm SRAMs at Concordia Station in Antarctica

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Radiation Study of a 4Mbit Ferroelectric RAM for Space Applications

International audienceWe present a Heavy Ion radiation study for a ultra low power non volatile 4Mbit ferroelectric memory(FRAM) for space applications manufactured on a 130nm domestic CMOS technology node. The radiation summary includes SEU data from Heavy Ions static as well as dynamic stress tests. The FRAM device meets the space level upset criteria for static device stress, but requires additional system mitigation for dynamic device stress