Research On Fault Diagnosis Technology Of Digital-Analog Hybrid Circuit Based On FMEA Analysis

With the rapid development of the electronics industry,the degree of integration of circuits is increasing.Many circuits that traditionally use analog technology are gradually being replaced by digital-analog hybrid technology.Integrating digital and analog signals on the same board not only improves performance,but also reduces board size and cost.The high level of integration of board-level circuits has made the requirements for reliability and fault diagnosis increasingly urgent.Traditional failure analysis methods that rely on professional experience and related equipment have been difficult to adapt to current fault analysis requirements.Failure Mode and Effect Analysis(FMEA)is an important method in reliability analysis and is often used for fault analysis of electronic systems.This paper will study the FMEA analysis and fault diagnosis of a digital-analog hybrid board-level circuit.The main research content includes the following three aspects:1.Perform FMEA analysis on a digital-analog hybrid circuit.Apply the FMEA analysis method to the board level circuit.The acquisition method of fault mode and the fault impact analysis method based on simulation are mainly studied.We studied the method of fault mode acquisition of circuit components and analyzed the applicability of fault mode simulation.Through the Saber simulation software,the fault impact analysis of the circuit is carried out.According to the characteristics of the Saber software,this paper proposes a method for automatic fault simulation through the netlist file and the command file.By modifying the circuit netlist file,we can integrate the fault modeling and fault injection of the circuit.By modifying the command file,we can set up the simulation analysis that needs to be performed and the feature response that needs to be extracted.In the end,we build the FMEA analysis table of the circuit module for the digital-analog hybrid delay.2.Fault diagnosis method based on FMEA analysis.This paper studies the fault diagnosis method based on the FMEA analysis table of the circuit.When diagnosing circuit faults,we expect to diagnose faulty components with as few test points and little test time as possible.And take corresponding compensation measures after locating the faulty components.According to the FMEA analysis table and the research requirements,this paper proposes a fault diagnosis method.Firstly,we convert the results of the FMEA analysis into a fault source-test dependency matrix.Then use the AO* algorithm to generate the optimal fault diagnosis tree and test sequence.We can perform circuit fault diagnosis based on the fault diagnosis tree.3.Design and implementation of Automated FMEA Software.This software mainly includes three modules: circuit automatic simulation,dependency matrix conversion and fault diagnosis.This software can realize the function of fault simulation and fault diagnosis of the circuit.Finally,this paper verifies the function and feasibility of the software through an example.