Analog circuits testing by means of walsh-hadamard spectrum of supply current transient state monitoring

The paper presents a practical technique of the analog circuits testing based on its supply current waveform evaluation. The decision about an actual circuit under test state is made during the circuit power turn on stage. The step of the supply voltage with an assumed rise time stimulates the circuit and the differential of its current response is decomposed by means of Walsh-Hadamard transform. The analysis of the spectra in the sequences domain allows to detect faults presence effectively. Finally, after the circuit testing on launching stage, only in case of its healthy state confirmation, it is admitted for use. Thanks to the minimal computational effort necessary for the applied kind of transformation, the proposed method is suitable to build in reliable systems with the use of a cheap microcontroller. Besides, the numerical complexity of the method can be easily reduced additionally by the set of the observed spectra points minimization by means of genetic algorithm.