17 research outputs found

    Thermal Radiometer Signal Processing Using Radiation Hard CMOS Application Specific Integrated Circuits for Use in Harsh Planetary Environments

    Get PDF
    Thermal radiometers such as proposed for the Europa Clipper flyby mission require low noise signal processing for thermal imaging with immunity to Total Ionizing Dose (TID) and Single Event Latchup (SEL). Described is a second generation Multi- Channel Digitizer (MCD2G) Application Specific Integrated Circuit (ASIC) that accurately digitizes up to 40 thermopile pixels with greater than 50 Mrad (Si) immunity TID and 174 MeV-sq cm/mg SEL. The MCD2G ASIC uses Radiation Hardened By Design (RHBD) techniques with a 180 nm CMOS process node

    Evaluation of Pulse Counting for the Mars Organic Mass Analyzer (MOMA) Ion Trap Detection Scheme

    Get PDF
    The Mars Organic Mass Analyzer is being developed at Goddard Space Flight Center to identify organics and possible biological compounds on Mars. In the process of characterizing mass spectrometer size, weight, and power consumption, the use of pulse counting was considered for ion detection. Pulse counting has advantages over analog-mode amplification of the electron multiplier signal. Some advantages are reduced size of electronic components, low power consumption, ability to remotely characterize detector performance, and avoidance of analog circuit noise. The use of pulse counting as a detection method with ion trap instruments is relatively rare. However, with the recent development of high performance electrical components, this detection method is quite suitable and can demonstrate significant advantages over analog methods. Methods A prototype quadrupole ion trap mass spectrometer with an internal electron ionization source was used as a test setup to develop and evaluate the pulse-counting method. The anode signal from the electron multiplier was preamplified. The an1plified signal was fed into a fast comparator for pulse-level discrimination. The output of the comparator was fed directly into a Xilinx FPGA development board. Verilog HDL software was written to bin the counts at user-selectable intervals. This system was able to count pulses at rates in the GHz range. The stored ion count nun1ber per bin was transferred to custom ion trap control software. Pulse-counting mass spectra were compared with mass spectra obtained using the standard analog-mode ion detection. Prelin1inary Data Preliminary mass spectra have been obtained for both analog mode and pulse-counting mode under several sets of instrument operating conditions. Comparison of the spectra revealed better peak shapes for pulse-counting mode. Noise levels are as good as, or better than, analog-mode detection noise levels. To artificially force ion pile-up conditions, the ion trap was overfilled and ions were ejected at very high scan rates. Pile-up of ions was not significant for the ion trap under investigation even though the ions are ejected in so-called 'ion-micro packets'. It was found that pulse counting mode had higher dynamic range than analog mode, and that the first amplification stage in analog mode can distort mass peaks. The inherent speed of the pulse counting method also proved to be beneficial to ion trap operation and ion ejection characterization. Very high scan rates were possible with pulse counting since the digital circuitry response time is so much smaller than with the analog method. Careful investigation of the pulse-counting data also allowed observation of the applied resonant ejection frequency during mass analysis. Ejection of ion micro packets could be clearly observed in the binned data. A second oscillation frequency, much lower than the secular frequency, was also observed. Such an effect was earlier attributed to the oscillation of the total plasma cloud in the ion trap. While the components used to implement pulse counting are quite advanced, due to their prevalence in consumer electronics, the cost of this detection system is no more than that of an analog mode system. Total pulse-counting detection system electronics cost is under $25

    Single Event Transients in Low Voltage Dropout (LVDO) Voltage Regulators

    Get PDF
    This viewgraph presentation reviews the use of Low Voltage Dropout (LVDO) Voltage Regulators in environments where heavy ion induced Single Event Transients are a concern to the designers.Included in the presentation are results of tests of voltage regulators

    System-on-Chip Data Processing and Data Handling Spaceflight Electronics

    No full text
    This paper presents a methodology and a tool set which implements automated generation of moderate-size blocks of customized intellectual property (IP), thus effectively reusing prior work and minimizing the labor intensive, error-prone parts of the design process. Customization of components allows for optimization for smaller area and lower power consumption, which is an important factor given the limitations of resources available in radiation-hardened devices. The effects of variations in HDL coding style on the efficiency of synthesized code for various commercial synthesis tools are also discussed

    Paralog Studies Augment Gene Discovery: DDX and DHX Genes

    No full text
    PubMedID: 31256877Members of a paralogous gene family in which variation in one gene is known to cause disease are eight times more likely to also be associated with human disease. Recent studies have elucidated DHX30 and DDX3X as genes for which pathogenic variant alleles are involved in neurodevelopmental disorders. We hypothesized that variants in paralogous genes encoding members of the DExD/H-box RNA helicase superfamily might also underlie developmental delay and/or intellectual disability (DD and/or ID) disease phenotypes. Here we describe 15 unrelated individuals who have DD and/or ID, central nervous system (CNS) dysfunction, vertebral anomalies, and dysmorphic features and were found to have probably damaging variants in DExD/H-box RNA helicase genes. In addition, these individuals exhibit a variety of other tissue and organ system involvement including ocular, outer ear, hearing, cardiac, and kidney tissues. Five individuals with homozygous (one), compound-heterozygous (two), or de novo (two) missense variants in DHX37 were identified by exome sequencing. We identified ten total individuals with missense variants in three other DDX/DHX paralogs: DHX16 (four individuals), DDX54 (three individuals), and DHX34 (three individuals). Most identified variants are rare, predicted to be damaging, and occur at conserved amino acid residues. Taken together, these 15 individuals implicate the DExD/H-box helicases in both dominantly and recessively inherited neurodevelopmental phenotypes and highlight the potential for more than one disease mechanism underlying these disorders. © 2019 American Society of Human GeneticsNational Heart, Lung, and Blood Institute Aicardi Syndrome Foundation: 2T32NS043124-16 National Institute on Drug Abuse National Institute of Diabetes and Digestive and Kidney Diseases: K12 DK083014 National Heart, Lung, and Blood Institute Fondazione Telethon National Institute of Neurological Disorders and Stroke: U54-HG003273 GSP15001 Deutsche Forschungsgemeinschaft California Department of Fish and Game: LE 4223/1 National Human Genome Research Institute National Institutes of Health: K08 HG008986, DK088767 National Cancer Institute R01 NS058529, R35 NS105078 National Institute of Mental Health National Institute of Neurological Disorders and StrokeThis work was supported in part by grants UM1 HG006542 (J.R.L) and UM1 HG006493 (M.B.) from the National Human Genome Research Institute (NHGRI) and the National Heart, Lung, and Blood Institute (NHLBI) to the Baylor Hopkins Center for Mendelian Genomics and the University of Washington Center for Mendelian Genomics, R01 NS058529 and R35 NS105078 (J.R.L.) from the National Institute of Neurological Disorders and Stroke (NINDS), U54-HG003273 (R.A.G.) from NHGRI , and Telethon Undiagnosed Diseases Program (TUDP) GSP15001 (N.B.-P.) from the Telethon Foundation , and also by the Aicardi Syndrome Foundation. I.P. was supported by 2T32NS043124-16 through the National Institutes of Health . J.E.P. was supported by NHGRI K08 HG008986 . F.H. was supported by the National Institutes of Health ( DK088767 ). M.R.B. was supported by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) K12 DK083014 . D.L was supported by the Werner Otto Stiftung and the German Research Foundation ( DFG; LE 4223/1 ). The Genotype-Tissue Expression (GTEx) Project was supported by the Common Fund of the Office of the Director of the National Institutes of Health , and by the National Cancer Institute , NHGRI , NHLBI , the National Institute on Drug Abuse , the National Institute of Mental Health , and NINDS . The data used for the analyses described in this manuscript were obtained from the GTEx Portal on 10/29/18. The authors would like to thank Hans-Jurgen Kreienkamp for the help in identifying helicase core motifs and the Genome Aggregation Database (gnomAD) and the groups that provided exome and genome variant data to this resource. A full list of contributing groups can be found at https://gnomad.broadinstitute.org/about

    Self-aware services: Using bayesian networks for detecting anomalies in internet-based services

    No full text
    service management, anomaly detection, Bayesian networks, online learning, fault and performance management We propose a general architecture and implementation for the autonomous assessment of health of arbitrary service elements, as a necessary prerequisite to self-control. We describe a health engine, the central component of our proposed ‘Self-Awareness and Control ’ architecture. The health engine combines domain independent statistical analysis and probabilistic reasoning technology (Bayesian networks) with domain dependent measurement collection and evaluation methods. The resultant probabilistic assessment enables open, non-hierarchical communications about service element health. We demonstrate the validity of our approach using HP's corporate email service and detecting email anomalies: mail loops and a virus attack. We also present the results of applying on-line machine learning to this architecture and quantify the benefits of the Bayesian network layer

    The Effects of Architecture and Process on the Hardness of Programmable Technologies

    No full text
    Architecture and process, combined, significantly affect the hardness of programmable technologies. The effects of high energy ions, ferroelectric memory architectures, and shallow trench isolation are investigated. A detailed single event latchup (SEL) study has been performed

    Self-Aware Services: Using Bayesian

    No full text
    We propose a general architecture and implementation for the autonomous assessment of health of arbitrary service elements, as a necessary prerequisite to self- control. We describe a health engine, the central component of our proposed `SelfAwareness and Control' architecture. The health engine combines domain independent statistical analysis and probabilistic reasoning technology (Bayesian networks) with domain dependent measurement collection and evaluation methods. The resultant probabilistic assessment enables open, non-hierarchical communications about service element health. We demonstrate the validity of our approach using HP's corporate email service and detecting email anomalies: mail loops and a virus attack. We also present the results of applying on-line machine learning to this architecture, and quantify the benefits of the Bayesian network layer
    corecore