Built-in self-test (BIST) structures for analog circuit fault diagnosis with current test data

In order to increase the number of test points, while still keeping low pin overhead, a built-in self-test (BIST) structure has been proposed for analog circuit fault diagnosis with voltage test data. The authors present alternative BIST structures for fault diagnosis with current test data using current copiers. The current copiers make a practically identical copy of the current without the need of well-matched components. Thus the proposed BIST structure requires less chip area. The proposed structure allows simultaneous sampling of current test data at various test points and shifting of the data to the output portion for fault diagnosis. Results have also shown that the proposed BIST structure is fully testable