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Although several synthesis methods for asynchronous circuits exist, only limited test methodologies have been developed. This paper presents a built-in self-test (BIST) architecture for Multi-Threshold NULL Convention Logic (MTNCL) asynchronous circuits that utilizes an automated, industry-standard tool-based flow. The software procedure for, and hardware components to implement, BIST functionality are explained. To improve testing performance, the MTNCL pipeline is separated into multiple parallel BIST circuits, with standard pipeline components doubling as BIST circuitry to reduce area overhead. Results of this BIST architecture and software performance is explored for three different test cases looking at area impact and effects of varying the number of input patterns and initial seeds. Further refinements to fault exclusions based upon operating principles of MTNCL are developed to better depict actual fault coverage; and additional hardware modifications are proposed to improve controllability and observability to further increase fault coverage. [ABSTRACT FROM AUTHOR]

This paper presents functional high-temperature analog circuits in silicon carbide bipolar technology. The circuits will collectively form the analog signal conditioning block for a wireless telemetry system in an extreme environment (above 400°C). The signal conditioning block is composed of a low dc gain operational amplifier, a negative voltage charge pump (CP), an RC oscillator, and a voltage regulator. The circuits are tested up to 450°C. The measured open-loop gain for the amplifier at 450°C is 30 dB. The regulator provides approximately 9-V output at 450°C for a fixed load current of up to 18 mA and an applied reference of 4.5 V. The negative voltage CP requires an oscillating signal at its input, which is provided by the RC cross-coupled oscillator. The CP provides about −5 V at 450°C. [ABSTRACT FROM AUTHOR]

As advanced natural gas power generation systems evolve, the thrust for increased efficiencies and reduced emissions results in increasingly harsh conditions inside the turbine environment. These high temperatures, pressures and corrosive atmospheres result in accelerated rates of degradation, leading to failure of turbine materials and components. Wolfspeed, A Cree Company, Siemens Energy and Siemens Corporate Technology, in collaboration with the Department of Energy (DOE)'s National Energy Technology Laboratory are developing a reliable and long-term monitoring capability in the turbine hot gas path in the form of novel ceramic-based thermocouples and wide bandgap instrumentation electronics that will contribute to the overall reliability of gas turbines. When equipped with better monitoring and controls, power plants can operate with increased fuelburning efficiency, improved process dynamics and gas concentrations and increased overall longevity of the power plant components. This will result in increased turbine availability and a reduction in outages and maintenance costs. The technology being developed in this programis based on advanced techniques and innovations in nearly every aspect of high-temperature electronics, including materials, semiconductor devices, subcomponents, electronic packaging and system integration. The environment in which this wireless system must operate has continuous centrifugal loads with a gravitation force on the order of 16,000 times the force of gravity (16,000 g) and temperatures exceeding 400°C. This article will specifically discuss the background and motivation for the high-temperature instrumentation system and will explain the high-level electrical system, the construction of the instrumentation package, the techniques used for integration onto rotating components, as well as the wireless power and data transmission systems. In addition to the electrical andmechanical design, this article will also discuss results from laboratory bench testing as well as heated spin rig testing. Finally, this article will highlight the future direction of the instrumentation system evolution, with a final objective of insertion into Siemens natural gas turbine power plants. [ABSTRACT FROM AUTHOR]