Testing embedded building blocks is much more
difficult than testing their stand-alone counterparts, and
Experience gained from the development of digital
circuits invites us to move towards structural or faultdriven
test methods and explore Built-In Self-Test
(BIST) alternatives as well. Regarding emergent
analog structural test solutions, Oscillation-Based Test
(OBT) is worth attention since it is conceptually
simple, does not require strong circuit modifications
and can handle BIST without the penalty of dedicated,
additional on-chip signal generation hardware. OBT is
essentially a defect-driven test approach, and has been
successfully applied to some significant examples like
biquad filters, and some basic data converter circuits
[11-[61.