Testing of Analog/Mixed Signal ICs: Past, present and future

Testing of Analogue/Mixed Signal ICs has reached a transition point. In the past AMS testing was based on functional tests that ensured that the analogue specifications were met. Unfortunately this approach is expensive; testing an `analogue´ transistor can be 1000x more expensive than testing a digital transistor. What is even a bigger concern in industry is that a large fraction of the AMS test development takes place after first silicon. Digital blocks are up and running in hours while the AMS part typically takes days or weeks. As a result AMS test is in the critical path towards the customer. Hence, the specification-based functional-test approach is becoming very costly both from a test time point of view and from a test development point of view. Already for a number of years industry is exploring alternatives. In the tutorial a number of those alternatives are covered such as usages of DC measurements instead of dynamic measurements, BIST for AMS blocks, and structural test approaches. These approaches have the advantage that they enable shorter test times but also that it can be verified before tape-out, hence shifting the effort out of the critical path. The tutorial is concluded with an outlook on the future requirements that address a frame-work for fast verification, validation and characterization of AMS blocks and test requirements related to adaptive AMS blocks which adjust their performance over lifetime.