Oscillation Test Methodology for Built-In Analog Circuits

This article aims to describe the fundamentals of analog and digital testing methods to analyze the difficulties of analog testing and to develop an approach to test the analog components in a mixed signal circuit environment. Oscillation based, built-in self-test methodology for testing analog components in mixed-signal circuits, in particular, is discussed. A major advantage of the OBIST method is that it does not require any complex response analyzers and test vector generators which are costly Furthermore, since the oscillation frequency is considered to be digital it can be easily interfaced to test techniques dedicated to the digital part of the circuit under test (CUT). OBIST techniques show promise in detecting faults in mixed signal circuits and requires little modification of the CUT to improve the fault coverage. Extensive simulation results on some sample analog benchmark circuits are described in Spice format. KeywordsSystem on chip (SOC), built-in Self test (BIST), Oscillation based built-in self test(OBIST), Circuit Under Test(CUT), Design for Testabiltity (DFT).