Fault isolation on mixed signal device

This paper determines the failure mechanism of the mixed signal device by using the fault isolation technique. Fault isolation techniques like micro-probing liquid crystal, EMMI and OBIC allow us to pinpoint the defective location. The mixed signal device analysis in this paper is the COMBO I, TP3054N, consisting of a μ-law monolithic PCM CODEC/filters utilizing the A/D and D/A conversion architecture and a serial PCM interface. Various failure mechanisms have been analyzed using the fault isolation technique. Poly-fuse defects as well as FAB related defects were determined during the course of analysis. Successfully finding the failure mechanism allows short term corrective action to be taken as well as long term redesigns to be implemented. This in turn improves product performance and assures a more reliable design for the COMBO I device as well as the other devices in this area