On Fault Modeling for Dynamic MOS Circuits

Static nMOS and static CMOS circuits show some serious problems for fault modeling and testing. In this paper we point out, that most of these problems are avoided by using dynamic nMOS or dynamic CMOS circuits. Stuck-open faults in this case do not result in sequential behaviour. A logical fault model is presented, where a fault of a logic gate will cause either a faulty combinational function or a degradation of the performance. Integrated test tools for technology dependent logical fault models based on random self test techniques are presented.