Digital signature proposal for mixed-signal circuits

A new BIST structure, based on the information provided by the XY-operation (Lissajous curves) is introduced in this paper. A digital signature is obtained which is used to discriminate catastrophic as well as parametric defects. High fault coverage is achieved when applying the proposed BIST on an ITC'97 benchmark circuit where 92% of the catastrophic defects and 87.5% of the parametric defects analyzed produced digital signatures clearly distinguishable from the golden signature.