Indirect test of M-S circuits using multiple specification band guarding

Testing analog and mixed-signal circuits is a costly task due to the required test time targets and high end technical resources. Indirect testing methods partially address these issues providing an efficient solution using easy to measure CUT information that correlates with circuit performances. In this work, a multiple specification band guarding technique is proposed as a method to achieve a test target of misclassified circuits. The acceptance/rejection test regions are encoded using octrees in the measurement space, where the band guarding factors precisely tune the test decision boundary according to the required test yield targets. The generated octree data structure serves to cluster the forthcoming circuits in the production testing phase by solely relying on indirect measurements. The combined use of octree based encoding and multiple specification band guarding makes the testing procedure fast, efficient and highly tunable. The proposed band guarding methodology has been applied to test a band-pass Butterworth filter under parametric variations. Promising simulation results are reported showing remarkable improvements when the multiple specification band guarding criterion is used.Peer ReviewedPostprint (author's final draft

Test of dual axis accelerometers based on specifications compliance

Postprint (published version

Quality metrics for mixed-signal indirect testing

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An Efficient behavioral description frontend tool for mixed-mode SPICE simulation

Postprint (published version

Digital signature generator for mixed-signal testing

Ponència presentada al 14th IEEE European Test SymposiumEs presenta un nou generador de signatures digitals per controlar dues senyals anàlogues. Es presenta la tecnologia STM 65 nm per demostrar la viabilitat de la proposta.Postprint (published version

Verifying analog circuits based on a digital signature

Verification of analog circuit specifications is a challenging task requiring expensive test equipment and time consuming procedures. This paper presents a method for low cost parameter verification based on statistical analysis of a digital signature. A CMOS on-chip monitor and sampler circuit generates the digital signature of the CUT. The monitor composes two signals (x(t); y(t)) and divides the X-Y plane with nonlinear boundaries in order to generate a digital code for every analog (x; y) location. A metric to be used to discriminate the golden and defective signatures is also proposed. The metric is based on the definition of a discrepancy factor performing circuit parameter identification via statistical and pre-training procedures. The proposed method is applied to verify possible deviations on the natural frequency of a Biquad filter. Simulation results show the possibilities of the proposal.Postprint (published version

Built-In test of MEMS capacitive accelerometers for field failures and aging degradation.

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Analog circuit test based on a digital signature

Production verification of analog circuit specifica- tions is a challenging task requiring expensive test equipment and time consuming procedures. This paper presents a method for low cost on-chip parameter verification based on the analysis of a digital signature. A 65 nm CMOS on-chip monitor is proposed and validated in practice. The monitor composes two signals (x(t), y(t)) and divides the X-Y plane with nonlinear boundaries in order to generate a digital code for every analog (x, y) location. A digital signature is obtained using the digital code and its time duration. A metric defining a discrepancy factor is used to verify circuit parameters. The method is applied to detect possible deviations in the natural frequency of a Biquad filter. Simulated and experimental results show the possibilities of the proposal.Peer ReviewedPostprint (published version

Criteria for indirect measurements in M-S testing

Analog and mixed-signal circuit testing is a cballenging task demanding large amounts of resources. In order to battle against this drawback, alternate testing has been established as an eflicient way of testing analog and M-S circuits by using indirect measures instead of the classic specification based testing. In this work we propose the use of Kendall's Tau rank correlation coeflicient for rating the suitability of a set of candidate indirect measures to be used in mixed-signal testing. Such criterion is shown to be adequate since it allows to avoid or minimize information redundancy in the measures set. As a proof of concept, a 4th order band-pass Butterworth filter has been simulated under the presence of process variations. The circuit has been tested using a subset of measures selected according to minimum Kendall's Tau coeflicient. Analog test efliciency metrics are reported showing test misclassification rate is among the best 15% possible, therefore validating the proposal.Postprint (published version