Oscillation-Based Test in Mixed-Signal Circuits presents the development and experimental validation of the structural test strategy called Oscillation-Based Test – OBT in short. The results here presented allow to assert, not only from a theoretical point of view, but also based on a wide experimental support, that OBT is an efficient defect-oriented test solution, complementing the existing functional test techniques for mixed-signal circuits.
Driven by the need of reducing the defective circuits to a minimum, present-day fabrication technologies require design techniques been complemented by effective test procedures. In the case of digital ICs, there are many procedures to cope with test problems in an effective manner. However, analog integrated circuits or the analog part of a mixed-signal integrated circuit bring enormeous difficulties when dealing with the problem of how to test them adequately.
Analog circuits are difficult to test because there is a wide variety of analog building blocks, their specifications are very broad, and there is a strong dependency of circuit parameters on component variations. For mixed-signal ICs, where analog circuits must coexist with digital components, testing difficulties increase substantially because the access to both analog and digital blocks is severely restricted. The consequences are a reduced fault coverage, a higher test application time and a longer test development time.