An improved OBT strategy for untuned continuous-time analog filters

Oscillation-based test in a CCII-based bandpass filter

“…For 0.35μ CMOS, in almost all cases of detected faults (M16_D open fault being the exception), both the frequency and the amplitude of the measured signal are outside the fault-free limits. This would indicate (as it already was noticed in previous work [17][18][19]) that OBT can be effectively applied to this circuit using only one of the two output values.…”

“…3, the circuit is passed as fault-free. This margin has previously shown to account adequately for process variation [16][17][18][19] without passing faulty circuits. Tables 3 and 4 present the simulation results for short circuit and open circuit faults, respectively, both for 0.35μm CMOS.…”

“…In this way, it is possible to use the well-known metric of fault-coverage for qualifying the test [17][18][19]. In this work, we focus our attention on catastrophic faults at both device and circuit level.…”

Low-cost DC BIST for analog circuits: A case study

“…However, this technique seems be strongly limited when used in circuits implemented in deep submicron technologies [4,5]. Another useful technique called oscillation based test (OBT) was introduced in 1995 [6], and applied later to analog CMOS circuits with considerable success [7,8]. In the latter, a set of exhaustive (e-mail: fortunato.dualibe@umons.ac.be) simulations was performed showing a good fault coverage rate.…”

“…It is assumed that a fault in the CUT will produce alterations in the oscillation parameters and consequently they can be used as test attributes for determining if a given circuit is faulty or faultfree. Besides the simple idea behind OBT, difficulties associated with oscillation frequency dispersion [7,12], the inherent circuit complexity and testing time demanded for on chip measurement a of frequency not always results in a convenient OBT BIST implementation.…”