Focusing on the design of problem of fault diagnosis of analog circuit and classifier with support vector machines（SVMs）

a new method of fault dictionary based on directed acyclic graph SVMs classifier（DAGSVC） is presented

and a specification for estimating the average test complexity of the support vector machine classifier（SVC） is also compared.Two actual analog filter are tested to validate the proposed method

whose performance is proven to be superior to the traditional methods

such as "1-v-r"SVC and "1-v-1"SVC.The proposed method

being proper to perform analog circuit diagnosis and faults isolation

could also achieve almost the same diagnosis rate as the clustering binary tree SVC

whose test structure is not unique.