Analog Circuit Fault Detection Using Relative Amplitude and Relative Phase Analysis

Abstract

Original scientific paperA new method for detection of parametric faults occurring in analog circuits based on relative amplitude and relative phase analysis of the Circuit Under Test (CUT) is proposed. The relative amplitude is the common power change of the signals and the relative phase presents the relative phase offset of the signals. In the proposed method, the value of each component of the CUT is varied within its tolerance limit using Monte Carlo simulation. The upper and lower bounds of relative amplitude and phase of the CUT sampling series are obtained. While testing, the relative amplitude and phase value of the analog circuit are obtained. If any one of the relative amplitude and phase values exceed the bounds then the CUT is declared faulty. The effectiveness of the proposed method is validated through HSpice/MATLAB simulations of two benchmark circuits and the practical circuit test of TowThomas circuit.Key words: Relative amplitude, Relative phase, Parametric fault, Analog circuit, Fault detection Otkrivanje pogreške u analognim sklopovima analizom relativne amplitude i faze. U ovomečlanku predložena je nova metoda otkrivanja parametarskih pogrešaka u analognim sklopovima temeljena na analizi relativne amplitude i faze promatranog sklopa (eng. Circuit Under Test, CUT). Relativna amplituda predstavlja zajedničku promjenu snage signala, dok relativna faza predstavlja pomak u fazi meu signalima. U predloženoj metodi, koristeći Monte Carlo simulacije, vrijednost svake komponente CUT-a mijenja se unutar svojih granica tolerancije. Na taj način dobivaju se gornja i donja granica relativne amplitude i faze CUT uzoraka, dok se sama relativna amplituda i faza dobivaju tijekom testiranja. U slučaju da ijedan od tih dvaju faktora prelazi granicu, CUT se proglašava neispravnim. Učinkovitost predložene metode ispitana je pomoću HSpice/MATLAB simulacija nad dva referentna sklopa te na Tow-Thomas sklopu.Ključne riječi: relativna amplituda, relativna faza, parametarska pogreška, analogni sklop, otkrivanje neispravnosti