BUILT-IN SELF-TEST (BIST) STRUCTURE FOR ANALOG CIRCUIT FAULT-DIAGNOSIS

Historically, analog circuits have been tested with the aid of a “bed of nails” tester that allows one to make use of test data which are not accessible via the input and output terminals of the circuit board or chip. Unfortunately, modern electronic systems are often multilayered and/or coated, thereby limiting the applicability of the “bed of nails” concept. In this paper, an analog built-in self-test (BIST) structure for analog circuit fault diagnosis is presented to increase the numbers of test points, while still keeping low pin overhead. The BIST structure allows access to some internal nodes so that the fault diagnosis process can be significantly simplified. In addition, the BIST structure also allows designers to use one channel of an oscilloscope to simultaneously monitor multiple output waveforms of analog circuits or system. © 1990 IEEE