UNIFIED BUILT-IN SELF-TEST FOR FULLY DIFFERENTIAL ANALOG CIRCUITS

The reduction of test costs, especially in high safety systems, requir es that the same test strategy is employed for design validation, manu facturing and maintenance tests, and concurrent error detection. This unification of off-line and on-line tests has already been attempted f or digital circuits and it offers the advantage of serving to all phas es of a system lifetime. Market pressure originating from the high cos ts of analog and mixed signal testing has resulted in renewed efforts for the test of analog parts. In this paper, off-line and on-line test techniques for fully differential analog circuits are presented withi n an unified approach. The high performance of these circuits makes th em very popular for many applications, including high safety, low volt age and high speed systems. A test master compliant with IEEE Std. 114 9.1 is described. The Analogue Unified BIST (AUBIST) is exemplified fo r linear and non-linear witched-capacitor circuits. High fault coverag e is achieved during concurrent/on-line testing. An off-line test ensu res the goal of self-checking circuits and allows the diagnosis of fau lty parts. The self-test of the AUBIST circuitry is also considered.