An analog cell to detect single event transients in voltage references

A reliable voltage reference is mandatory in mixed-signal systems. However, this family of components can undergo very long single event transients when operating in radiation environments such as space and nuclear facilities due to the impact of heavy ions. The purpose of the present paper is to demonstrate how a simple cell can be used to detect these transients. The cell was implemented with typical {COTS} components and its behavior was verified by {SPICE} simulations and in a laser facility. Different applications of the cell are explored as well

Laser tests on a power operational amplifier

Laser tests on a power operational amplifier were performed to investigate its sensitivity to single event transients. These tests apparently point out to this device being quite insensitive to single event transients so it would become a good candidate to develop power systems to be used in radiation environments

Defining a strategy to perform life-tests with analog devices

Unlike for memory elements inside integrated circuits, scarce life tests have been performed to study single event transients in discrete analog devices. The reason is that life tests require a large amount of samples to be stored for having enough data allowing statistical conclusions and, usually, single event transients are captured by means of oscilloscopes. In this paper, we propose a strategy to carry out life tests in analog voltage comparators by means of digital programmable device that can detect anomalous pulses in the voltage comparator. Besides, the idea on which this kind of tests relies can be extended to be used with other families of analog devices, such as operational amplifiers, voltage references, etc

Inducción de sucesos aislados en memoria SRAM (Induced single events in SRAMs)

Este proyecto consiste en emular los errores producidos en memorias semiconductoras por la radiación atmosférica mediante un láser pulsado que actúa de modo semejante a un ión. Se realiza un mapa de sensibilidad de la memoria identificando los puntos susceptibles de error y cuántos errores simultáneos se producen. Para ello es necesario realizar pasos muy delicados como desencapsular la memoria, construir placas de test tanto para el circuito examinado como para el sistema de caracterización, conseguir, mediante obturadores, la incidencia de un único pulso sobre la memoria, diseñar un sistema de adquisición de datos, fijar la energía y camino óptico del láser pulsado así como controlar de manera automática la posición en el plano XY donde incide el láser. Los resultados muestran que algunas zonas de la memoria son insensibles al láser en tanto que otras tienen una sensibilidad extremadamente alta. Por otra parte, se observa la existencia de dos tipos distintos de errores, uno llamado Single Event Upset (SEU) y, otro menos habitual, llamado Single Event Micro-latchup. [ABSTRACT] This project is to emulate the errors in semiconductor memories for atmospheric radiation by pulsed laser that acts as an ion. A sensitivity map of the memory is performed identifying potential error areas and how many errors occur simultaneously. This requires very delicate steps, like unencapsulate memory, build test boards for the studied circuit and the characterization system, getting, through shutters, the incidence of a single pulse on memory, design an acquisition system data, set the energy laser and laser optical path and automatically controlling the position in the XY plane where the laser hits. The results show that some memory zones are insensitive to the laser while others have an extremely high sensitivity. Moreover, two distinct types of errors are observed, one called Single Event Upset (SEU) and other less common, called Single Event Micro-latchup

Emulación por láser de la radiación cósmica en memorias y comparación con la radiación natural e inducida

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Físicas, Departamento de Física Aplicada III (Electricidad y Electrónica), leída el 08/07/2014Depto. de Estructura de la Materia, Física Térmica y ElectrónicaFac. de Ciencias FísicasTRUEunpu

SPICE Simulations of single event transients in bipolar analog integrated circuits using public information and free open source tools

This paper proposes a technique to build SPICE micromodels of integrated circuits in bipolar technology appropriate to simulate single event transients. First of all, we will show how to obtain SPICE models of the internal transistors from texts in the scientific and academic literature. Next, several strategies to figure out the internal structure of the integrated circuits and bias point will be shown. Finally, simulation results will be compared to data issue from experiments, either performed by the authors or by other researchers. As the simulations do not require expensive software or hardware, this paper can be a start point for research groups with small budget or for academic purposes at universities

Characteristics of the long duration pulses in a shunt linear voltage regulator

Shunt linear voltage regulators are still used in situations where other kinds of regulators are not advised. This paper explores a mechanism liable to induce long duration pulses ( ~ 100 μ s ) in these devices, which is eventually demonstrated using a pulsed laser facility. Data issued from these tests helps to understand how the electrical network parameters as well as the non-idealities of the devices affect the characteristics of the transients. Finally, this phenomenon is investigated in similar structures with identical purpose

Laser induced single events in SRAMs

This paper is aimed at emulating the errors in semiconductor memories by space radiation with a pulsed laser that acts as an ion. A sensitivity map of the memory is performed identifying potential error areas and how many errors simultaneously occur

Peak detector effect in low-dropout regulators

The peak detector effect is a phenomenon that makes single event transients much longer once an error amplifier switches from linear to saturation zone due to the presence of external capacitors. This is so-called since it was discovered in a simple voltage reference in which a parasitic lossy peak detector was unwillingly built in the output stage. In this paper, peak detector effect is generalized to explain the appearance of long duration pulses in typical low dropout voltage regulator built with discrete devices. This effect has been related to the way in which the negative feedback loop is closed and to the kind of pass device in the output stage. Thus, if the linear voltage regulator consists in an error amplifier the output of which controls a current source, the peak detector effect will occur if the current source is unidirectional, the output load does not drain enough current and is in parallel with an external capacitor

Sistema autónomo de detección y almacenamiento de errores por sucesos aislados en SRAMs

En esta contribución se explica el diseño, fabricación y verificación experimental de un sistema automático de lectura y escritura de memorias SRAM cuyo objeto es la determinación de la tasa de errores asociados a la acción de los rayos cósmicos e impurezas radiactivas en esa tecnología de fabricación. Se ha concebido este sistema para que se pudiera construir en una placa de reducidas dimensiones y que, de este modo, pudiera transportarse en la cabina de un avión durante vuelos comerciales