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Discrete hard fault is always tested in existing node selection methods for analog circuit diagnosis. Actually, analog component parameter changes continuously and output node voltages distribute in a continuous voltage interval. In this paper, an novel test node selection method is proposed for continuous parameter shifting (CPS) fault. Firstly, CPS faults are sampled by parameter scan simulation in a single test frequency. Collected node voltages are seen as a data set in a statistical distribution. Secondly, ambiguous faults are identified according to the independent distributions of all CPS faults. The independence of CPS fault sample is deduced by Kruskal-Wallis non-parametric testing. Then, new fault dictionaries are generated for each test node according to ambiguous interval. The proposed fault dictionary represents the mutual independence of each pair of CPS faults. Finally, as fault dictionaries are considered as connected graphs, the optimal test nodes are selected based on an improved depth first search (DFS) algorithm. The effectiveness of method is verified by testing linear and nonlinear circuits. [ABSTRACT FROM AUTHOR]

A new capacitive structure for tilt sensor based on the MEMS technology is designed, analyzed and simulated. With a detailed analysis, we achieve to a precise relation between capacitance and inclination angle. Taking advantage of cylindrical structure in our design, we reach to a linear relationship between capacitance and tilt angle. In three designs of our capacitive tilt micro-sensor, there are 1, 2 and 4 micro capacitors. These capacitors have a common plate of mercury which is movable. Another plate is fixed. Displacement of mercury according to the deflection tends to the variations of capacitors and subsequently total capacitance of the tilt micro-sensor changes. In each of three designs for this micro-sensor, output capacitance (C) is introduced with a special equation for obtaining a linear and continues relationship between C and tilt angle. The last proposed micro-sensor structure with 4 micro capacitors, shows linear relationship for C over tilt measurement range of -180° to +180° on one axis besides proper sensitivity. [ABSTRACT FROM AUTHOR]