A regulated high negative voltage generator for single-photon avalanche photodiodes

In this work, a regulated high negative voltage generator for biasing single-photon avalanche photodiodes (SPAD) was developed. The circuit provides up to -70 V from a positive voltage source. This circuit allows users to control the negative output voltage using a positive voltage rail, thus eliminating the requirement of a negative voltage for the negative voltage control. This approach simplifies the setting of the output and facilitates integration in miniaturized photon counting systems. The testing on a fabricated PCB of this circuit show that the output voltage can be accurately controlled up to -70 V with ripples of less than 80 mV. A SPAD based experimental setup was also built and the experimental results show that the circuit is able to maintain a stable bias voltage for a planar SPAD at both low and high counting rates

Mixed-source charger-supply CMOS IC

The proposed research objective is to develop, test, and evaluate a mixer and charger-supply CMOS IC that derives and mixes energy and power from mixed sources to accurately supply a miniaturized system. Since the energy-dense source stores more energy than the power-dense source while the latter supplies more power than the former, the proposed research aims to develop an IC that automatically selects how much and from which source to draw power to maximize lifetime per unit volume. Today, the state of the art lacks the intelligence and capability to select the most appropriate source from which to extract power to supply the time-varying needs of a small system. As such, the underlying objective and benefit of this research is to reduce the size of a complete electronic system so that wireless sensors and biomedical implants, for example, as a whole, perform well, operate for extended periods, and integrate into tiny spaces.Ph.D

Design and Control of Power Converters 2019

In this book, 20 papers focused on different fields of power electronics are gathered. Approximately half of the papers are focused on different control issues and techniques, ranging from the computer-aided design of digital compensators to more specific approaches such as fuzzy or sliding control techniques. The rest of the papers are focused on the design of novel topologies. The fields in which these controls and topologies are applied are varied: MMCs, photovoltaic systems, supercapacitors and traction systems, LEDs, wireless power transfer, etc

Renewable Energy

Renewable Energy is energy generated from natural resources - such as sunlight, wind, rain, tides and geothermal heat - which are naturally replenished. In 2008, about 18% of global final energy consumption came from renewables, with 13% coming from traditional biomass, such as wood burning. Hydroelectricity was the next largest renewable source, providing 3% (15% of global electricity generation), followed by solar hot water/heating, which contributed with 1.3%. Modern technologies, such as geothermal energy, wind power, solar power, and ocean energy together provided some 0.8% of final energy consumption. The book provides a forum for dissemination and exchange of up - to - date scientific information on theoretical, generic and applied areas of knowledge. The topics deal with new devices and circuits for energy systems, photovoltaic and solar thermal, wind energy systems, tidal and wave energy, fuel cell systems, bio energy and geo-energy, sustainable energy resources and systems, energy storage systems, energy market management and economics, off-grid isolated energy systems, energy in transportation systems, energy resources for portable electronics, intelligent energy power transmission, distribution and inter - connectors, energy efficient utilization, environmental issues, energy harvesting, nanotechnology in energy, policy issues on renewable energy, building design, power electronics in energy conversion, new materials for energy resources, and RF and magnetic field energy devices

Battery-sourced switched-inductor multiple-output CMOS power-supply systems

Wireless microsystems add intelligence to larger systems by sensing, processing and transmitting information which can ultimately save energy and resources. Each function has their own power profile and supply level to maximize performance and save energy since they are powered by a small battery. Also, due to its small size, the battery has limited energy and therefore the power-supply system cannot consume much power. Switched-inductor converters are efficient across wide operating conditions but one fundamental challenge is integration because miniaturized dc-dc converters cannot afford to accommodate more than one off-chip power inductor. The objective of this research is to explore, develop, analyze, prototype, test, and evaluate how one switched inductor can derive power from a small battery to supply, regulate, and respond to several independent outputs reliably and accurately. Managing and stabilizing the feedback loops that supply several outputs at different voltages under diverse and dynamic loading conditions with one CMOS chip and one inductor is also challenging. Plus, since a single inductor cannot supply all outputs at once, steady-state ripples and load dumps produce cross-regulation effects that are difficult to manage and suppress. Additionally, as the battery depletes the power-supply system must be able to regulate both buck and boost voltages. The presented system can efficiently generate buck and boost voltages with the fastest response time while having a low silicon area consumption per output in a low-cost technology which can reduce the overall size and cost of the system.Ph.D

Recent Development of Hybrid Renewable Energy Systems

Abstract: The use of renewable energies continues to increase. However, the energy obtained from renewable resources is variable over time. The amount of energy produced from the renewable energy sources (RES) over time depends on the meteorological conditions of the region chosen, the season, the relief, etc. So, variable power and nonguaranteed energy produced by renewable sources implies intermittence of the grid. The key lies in supply sources integrated to a hybrid system (HS)

Birefringent and diffractive devices for implementing multi-Gbit/s transmission systems using visible WDM over SI-POF technology

Mención Internacional en el título de doctorNew optical devices are indispensable for the development of the future SI−POF high speed short−range communication networks and as well as in many sensors applications based on SI−POFs. These devices are not well established to date due to the physical and multimodal characteristics of the SI−POF technology as well as the characteristics of the SI−POF visible WDM systems. Therefore, the main objective that has been established for this research work is to develop new optical components based primarily on liquid crystals and diffractive elements for applications in advanced optical communication systems with plastic optical fibers, ensuring an optimized power consumption to reduce the carbon footprint of ICTs.Se necesitan nuevos dispositivos ópticos en el rango visible para el desarrollo de las futuras redes de comunicación de alta velocidad y corto alcance basadas en SI−POF. Estos dispositivos también son de gran utilidad en muchas aplicaciones de sensores basados en POF. Los diseños de estos dispositivos no están bien establecidos hasta la fecha debido a las características físicas y multimodales de la tecnología SI−POF, así como las características de los sistemas WDM en el visible. Por lo tanto, el principal objetivo que se ha establecido para este trabajo de investigación es el desarrollo de nuevos dispositivos ópticos basados principalmente en cristales líquidos y elementos de difracción para aplicaciones en sistemas avanzados de comunicaciones ópticas con fibras ópticas de plástico de salto de índice, lo que garantiza un consumo de energía optimizado para reducir la huella de carbono en esta tecnología en el sector TIC.Programa en Ingeniería Eléctrica, Electrónica y AutomáticaPresidente: Rajeev J. Ram.- Vocal: Bruno Fracasso.- Secretario: Javier Mateo Gascó