A CASE STUDY OF MIXED SIGNAL FAULT ISOLATION: KNOWLEDGE BASED VS. DECISION TREE PROGRAMMING

Comparison of current design and functional test practices for digital circuits versus analog circuits reveals a significant lag in the availability and sophistication of analog design tools, DFT techniques, design-to-test links, and diagnostic aides. Though hardware advances such as VXI and software advances such as the Standard Commands for Programmable Instruments (SCPI) reduce the time and expense of developing analog gobo go functional test programs, there has not been a similar advance in analog diagnostics. As a result, most electronic manufacturers and depots rely on skilled technicians to manually troubleshoot functional test failures. The scarcity and cost of skilled technicians and the increasing mix and complexity of analog (and mixed signal) circuits point to a strong need for automated analog diagnostics.