En este artículo se realiza una breve revisión acerca de las estrategias de diagnóstico utilizadas en el diseño y fabricación de circuitos integrados analógicos en general, pero haciendo énfasis en los utilizados en comunicaciones. Se... more
En este artículo se realiza una breve revisión acerca de las estrategias de diagnóstico utilizadas en el diseño y fabricación de circuitos integrados analógicos en general, pero haciendo énfasis en los utilizados en comunicaciones. Se exponen los nuevos paradigmas que rigen el diseño electrónico moderno. A la luz de estos paradigmas, luego se revisan los aspectos más relevantes del diseño microelectrónico moderno, desde una perspectiva cualitativa, así como una exploración breve acerca de los tipos de diagnóstico que podemos encontrar partiendo de las fallas que los originan. Se introducen luego algunas estrategias más usuales para el diagnostico de circuitos integrados de comunicaciones, así como algunas aproximaciones neuronales. Se discute acerca de los aspectos que hacen tan particular el diseño y diagnostico de circuitos integrados de comunicaciones y la comparativa entre las distintas técnicas. Finalmente se propone una estrategia neuronal que combina la técnica MADBIST con una red neuronal para realizar el diagnostico.
Highly accelerated life test (HALT) is a test methodology to evaluate reliability of mechanical and electromechanical devices. HALT is often used on devices that must be guaranteed for high reliability over a long time span. HALT... more
Highly accelerated life test (HALT) is a test methodology to evaluate reliability of mechanical and electromechanical devices. HALT is often used on devices that must be guaranteed for high reliability over a long time span. HALT simulates the life cycle of the device, usually until it experiments a failure. HALT tests are used to assess reliability of devices at the end of the production cycle, but are also used to improve the design and manufacturing process, allowing to find and correct potential problems when changes to the production process are less costly. HALT tests are usually difficult and time consuming, and there is a strong need for their automation. This paper proposes a methodology to design software and hardware for HALT automated tests. The goals pursued are to standardize the test process, to reduce the need for manual commands at the minimum and to simplify the data gathering process. The methodology proposed starts from domain requirement analysis and is conceived to be as general as possible, with the goal to make it easily extensible and adaptable to multiple testing domains. Finally, the paper reports on a case study describing a HALT test device designed according to the proposed methodology and currently in use to test electromechanical actuators.
This article describes the computational model of a 2nd order Σ-Δ modulator used to generate Pulse-density Modulated (PDM) signals. Such a model was required as part of a previous work carried by one of the authors in order to perform... more
This article describes the computational model of a 2nd order Σ-Δ modulator used to generate Pulse-density Modulated (PDM) signals. Such a model was required as part of a previous work carried by one of the authors in order to perform design verification of analog integrated circuits. For this purpose, the theoretical performance of the Σ-Δ modulators was studied, and the mathematical model of the latter was performed using finite difference equations under coherent sampling. After this, the modulator was implemented using Matlab™ mathematical model. Then, it was verified that it behaved according to the theory of Σ-Δ modulation by performing simulations. As this work is complementary to a previously developed one, as already mentioned, we were careful that the stimuli encoded in the PDM signals was recoverable through a low pass filtering. Therefore, such filter was implemented in Matlab™, and after that we applied the PDM signals to its input. The result was the successful recovery of the stimuli, but with remaining noise outside and within the band of interest. It was evident that filtering was not able to remove the noise completely.
