I. Lopez-Calle

Bio: I. Lopez-Calle is an academic researcher from Complutense University of Madrid. The author has contributed to research in topics: Laser & Operational amplifier. The author has an hindex of 5, co-authored 16 publications receiving 55 citations. Previous affiliations of I. Lopez-Calle include European Space Agency.

SRAMs SEL and SEU in-flight data from PROBA-II spacecraft

Abstract: This paper presents an analysis of the SEE in-flight data of SRAMs on board Proba-II spacecraft. Proba-II spacecraft has been flying on a LEO orbit for more than 3 years. Observed in-flight error rates are compared with predictions based on ground test data.

Modification of the LM124 Single Event Transients by Load Resistors

Abstract: The influence of a load resistor on the shape of the single event transients was investigated in the LM124 operational amplifier by means of laser tests. These experiments indicated that, as a general rule, load resistors modify the size of the transients. SPICE simulations helped to understand the reasons of this behavior and showed that the distortion is related to the necessity of providing or absorbing current from the load resistor, which forces the amplifier to modify its operation point. Finally, load effects were successfully used to explain the distortion of single event transients in typical feed-back networks and the results were used to explain experimental data reported elsewhere.

Peak Detector Effect in Low-Dropout Regulators

Abstract: 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.

Simulation of femtosecond pulsed laser effects on MOS electronics using TCAD Sentaurus customized models

Abstract: Pulsed laser illumination constitutes an excellent tool to emulate the effects produced by the impact of highly energetic particles on electronic circuits. Numerical simulation techniques could be used to study these effects and to establish accurate relationships between the laser parameters and the particle characteristics. Unfortunately, although particle incidence can be accurately simulated, up to now, there not exist a simulation technique able to reproduce completely the effects in electronics produced by a femtosecond pulsed laser. In this paper, we explore the Synopsys Sentaurus TCAD ability to simulate the effects of pulsed laser illumination. Theoretical study of the physics of the laser–semiconductor interactions leads us to design a new simulation tool. Modifying the heavy ion generation rate included in Sentaurus TCAD, we can take into account all the theoretical predicted characteristics of femtosecond laser illumination, and reproduce the single event effects (SEE) found in experimental tests. Copyright © 2010 John Wiley & Sons, Ltd.

LASER system for space environment emulation

Abstract: The Sensors and Electronic Instrumentation Group of the University Complutense of Madrid has developed a system to emulate the cosmic radiations effects on electronic devices by LASER irradiations. Of great interest to the nuclear industry and space electronics, this project was carried out partially supported by the company ALTER SPAIN S.A., specialized in engineering, quality management and testing of high reliability electronic components for space applications.

Single event effects in high-energy accelerators

Abstract: The radiation environment encountered at high-energy hadron accelerators strongly differs from the environment relevant for space applications. The mixed-field expected at modern accelerators is composed of charged and neutral hadrons (protons, pions, kaons and neutrons), photons, electrons, positrons and muons, ranging from very low (thermal) energies up to the TeV range. This complex field, which is extensively simulated by Monte Carlo codes (e.g. FLUKA) is due to beam losses in the experimental areas, distributed along the machine (e.g. collimation points) and deriving from the interaction with the residual gas inside the beam pipe. The resulting intensity, energy distribution and proportion of the different particles largely depends on the distance and angle with respect to the interaction point as well as the amount of installed shielding material. Electronics operating in the vicinity of the accelerator will therefore be subject to both cumulative damage from radiation (total ionizing dose, displacement damage) as well as single event effects which can seriously compromise the operation of the machine. This, combined with the extensive use of commercial-off-the-shelf components due to budget, performance and availability reasons, results in the need to carefully characterize the response of the devices and systems to representative radiation conditions.

Compact Modeling and Simulation of Heavy Ion-Induced Soft Error Rate in Space Environment: Principles and Validation

Abstract: A simple physical model for calculation of the ion-induced soft error rate in space environment has been proposed, based on the phenomenological cross-sectional notion. The proposed numerical procedure is adapted to the multiple cell upset characterization in highly scaled memories. Nonlocality of the ion impact has been revealed as the key concept determining the difference between physical processes in low-scaled and highly scaled memories. The model has been validated by comparison between the simulation results and the literature on-board data. It was shown that the proposed method provides single-valued prediction results correlating well with on-board data-based solely on cross-sectional data and LET spectra without any hidden fitting parameters and procedures.

Correction of Single Event Latchup Rate Prediction Using Pulsed Laser Mapping Test

Abstract: Most classical approaches of single event effect rate prediction are based on the rectangular parallelepiped model of sensitive volume. However it is not clear about the number of sensitive volume in the device when predicting the in-flight single event latchup rate. As for memory device, there are two empirical practices to deal with the latchup sensitive volume number: one assumes that there is only one sensitive volume in the whole device; another assumes that there are as much sensitive volumes as the number of memory cells. The latchup sensitive volume number of a 4M-bits SRAM is determined as 63360 using pulsed laser mapping test in this work first. Based on the two assumed and measured sensitive volume number, the single event latchup rates of the device are calculated and compared. The results show that pulsed laser could be a powerful tool to obtain the real sensitive volume number in the device, which is significant for single event latchup rate prediction. The latchup rate will be either overestimated or underestimated with the assumption of the sensitive volume number as one or as much as the number of memory cells.

The Role of Feedback Resistors and TID Effects in the ASET Response of a High Speed Current Feedback Amplifier

Abstract: The influence of external circuit designs on ASET shapes in a high speed current feedback amplifier (CFA) (AD844) is investigated by means of the pulsed laser single event effect (PLSEE) simulation technique. Changes of the feedback resistors modify circuit’s electrical parameters such as closed-loop gain and bandwidth, affecting amplifier stability and so ASET shapes. Qualitative explanations based on general electronic rules and feedback theories enable the understanding of a CFA operation establishing a correlation between the evolution of external feedback resistor values and ASET parameters. TID effects on the ASET sensitivity in AD844 CFA are also investigated in this work highlighting different behaviors according to the impacted bipolar transistor in the integrated circuit.

SPICE Simulations of Single Event Transients in Bipolar Analog Integrated Circuits Using Public Information and Free Open Source Tools

Abstract: 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.