Ultra High Voltage IC design with a 400V CMOS technology: a dimmer application

The advent of Ultra High Voltage (UHV) technologies for integrated circuit fabrication opens up new possibilities for the design of circuits that connect directly to the power distribution network, with applications in the design of compact power sources, domotics, smart-grids, etc. This project proposes the design, fabrication and characterization of circuits in an UHV technology, of which a fully integrated two terminal phase-cut dimmer was chosen as an example. At the time of writing this thesis, no commercially available integrated circuit exists that fully implements a phase cut dimmer, and no academic papers could be found referencing similar circuits. The circuit was designed on a 1µm UHV MOS technology in a silicon-on-insulator (SOI) wafer (XDM10 from XFAB). The dimmer can operate with a duty cycle of up to 95% power (80% time) and a load of up to 100W which is adequate for modern domestic dimmable LED lights. The total occupied silicon area is 6.5mm2 without pads. Because of technological limitations, the final version of the dimmer is almost fully integrated. Two low voltage capacitors and four UHV diodes are outside the ASIC.Con la popularización de tecnologías de fabricación de circuitos integrados de ultra alto voltaje (UHV), surge la posibilidad de diseñar circuitos integrados conectados directamente a la red de distribución, con aplicaciones en fuentes compactas, domótica, smart-grids, entre otras. Este proyecto propone el diseño, fabricación y caracterización de circuitos en tecnología UHV. Se toma como ejemplo un atenuador por corte de fase de dos terminales. Al momento de escribir esta tesis, no existen circuitos integrados comerciales que implementan un atenuador por corte de fase completo, ni se pudo encontrar artículos académicos haciendo referencia a dispositivos similares. El circuito fue diseñado en una tecnología de 1µm UHV MOS (XDM10 de XFAB) en una oblea de silicio sobre aislante (SOI). Puede operar con un ciclo de trabajo hasta 95% de potencia (80% en tiempo) y una carga de hasta 100W, lo que es adecuado para lámparas atenuables de LED. El área total de silicio ocupada es de 6.5mm2 sin contar pads. Debido a limitaciones tecnológicas, la versión final del atenuador es casi completamente integrada. Dos capacitores de bajo voltaje y cuatro diodos UHV quedan por fuera del ASIC

Design Techniques of Highly Integrated Hybrid-Switched-Capacitor-Resonant Power Converters for LED Lighting Applications

The Light-emitting diodes (LEDs) are rapidly emerging as the dominant light source given their high luminous efficacy, long lift span, and thanks to the newly enacted efficiency standards in favor of the more environmentally-friendly LED technology. The LED lighting market is expected to reach USD 105.66 billion by 2025. As such, the lighting industry requires LED drivers, which essentially are power converters, with high efficiency, wide input/output range, low cost, small form factor, and great performance in power factor, and luminance flicker. These requirements raise new challenges beyond the traditional power converter topologies. On the other hand, the development and improvement of new device technologies such as printed thin-film capacitors and integrated high voltage/power devices opens up many new opportunities for mitigating such challenges using innovative circuit design techniques and solutions. Almost all electric products needs certain power delivery, regulation or conversion circuits to meet the optimized operation conditions. Designing a high performance power converter is a real challenge given the market’s increasing requirements on energy efficiency, size, cost, form factor, EMI performance, human health impact, and so on. The design of a LED driver system covers from high voltage AC/DC and DC/DC power converters, to high frequency low voltage digital controllers, to power factor correction (PFC) and EMI filtering techniques, and to safety solutions such as galvanic isolation. In this thesis, we study design challenges and present corresponding solutions to realize highly integrated and high performance LED drivers combining switched-capacitor and resonant converters, applying re-configurable multi-level circuit topology, utilizing sigma delta modulation, and exploring capacitive galvanic isolation. A hybrid switched-capacitor-resonant (HSCR) LED driver based on a stackable switched-capacitor (SC) converter IC rated for 15 to 20 W applications. Bulky transformers have been replaced with a SC ladder to perform high-efficiency voltage step-down conversion; an L-C resonant output network provides almost lossless current regulation and demonstrates the potential of capacitive galvanic isolation. The integrated SC modules can be stacked in the voltage domain to handle a large range of input voltage ranges that largely exceed the voltage limitation of the medium-voltage-rated 120 V silicon technology. The LED driver demonstrates > 91% efficiency over a rectified input DC voltage range from 160 VDC to 180 VDC with two stacked ICs; using a stack of four ICs > 89.6% efficiency is demonstrated over an input range from 320 VDC to 360 VDC . The LED driver can dim its output power to around 10% of the rated power while maintaining >70% efficiency with a PWM controlled clock gating circuit. Next, the design of AC main rectifier and inverter front end with sigma delta modulation is described. The proposed circuits features a pair of sigma delta controlled multilevel converters. The first is a multilevel rectifier responsible for PFC and dimming. The second is a bidirectional multilevel inverter used to cancel AC power ripple from the DC bus. The system also contains an output stage that powers the LEDs with DC and provides for galvanic isolation. Its functional performance indicates that integrated multilevel converters are a viable topology for lighting and other similar applications

Manned maneuvering unit technology survey

The preliminary design of the manned maneuvering unit (MMU) for the shuttle is investigated, and the current state of the art in certain technology areas that may find application on the operational EVA shuttle MMU is examined. Three broad areas of technology, namely: (1) mechanical energy storage - i.e., the practicality of utilizing the energy storage capability of either a reaction wheel or a control moment gyro, (2) numerical and alphanumerical displays, and (3) recent electronics developments such as microprocessors and integrated injection logic, were covered

LED Location Beacon System Based on Processing of Digital Images

This paper is in the field of vehicle positioning technology for the Intelligent Transportation Systems. The ideas of an innovative light-emitting diode (LED)-based location beacon system are developed and verified. The system developed is a combination of several latest technologies which include a CMOS vision sensor, high brightness LEDs, and digital image processing techniques. It belongs to a new kind of simplex communication link. A digital camera is used to capture images contained in the LED beacon signal. The captured digital images are processed by the algorithms developed and a location code is extracted. The location code can be used for calibration of a vehicle positioning system which may consist of a GPS, Inertial Navigation System (INS) and other sensors. The issues examined include the structure of the transmitter and the receiver, the signaling method, the transmission protocol of the LED panel, the relationship between the camera capturing rate and the LED pattern update rate, the digital camera exposure technology, and the efficiency of the image processing algorithms. Experiments using a prototype transmitter and a receiver were performed. The experimental results provide a good demonstration of the viability of the ideas and methodologies developed.published_or_final_versio

A Novel Boost Converter Based LED Driver Chip Targeting Mobile Applications

abstract: A novel integrated constant current LED driver design on a single chip is developed in this dissertation. The entire design consists of two sections. The first section is a DC-DC switching regulator (boost regulator) as the frontend power supply; the second section is the constant current LED driver system. In the first section, a pulse width modulated (PWM) peak current mode boost regulator is utilized. The overall boost regulator system and its related sub-cells are explained. Among them, an original error amplifier design, a current sensing circuit and slope compensation circuit are presented. In the second section – the focus of this dissertation – a highly accurate constant current LED driver system design is unveiled. The detailed description of this highly accurate LED driver system and its related sub-cells are presented. A hybrid PWM and linear current modulation scheme to adjust the LED driver output currents is explained. The novel design ideas to improve the LED current accuracy and channel-to-channel output current mismatch are also explained in detail. These ideas include a novel LED driver system architecture utilizing 1) a dynamic current mirror structure and 2) a closed loop structure to keep the feedback loop of the LED driver active all the time during both PWM on-duty and PWM off-duty periods. Inside the LED driver structure, the driving amplifier with a novel slew rate enhancement circuit to dramatically accelerate its response time is also presented.Dissertation/ThesisDoctoral Dissertation Electrical Engineering 201

Design and Testing of Electronic Devices for Harsh Environments

In this thesis an overview of the research activity focused on development, design and testing of electronic devices and systems for harsh environments has been reported. The scope of the work has been the design and validation flow of Integrated Circuits operating in two harsh applications: Automotive and High Energy Physics experiments. In order to fulfill the severe operating electrical and environmental conditions of automotive applications, a systematic methodology has been followed in the design of an innovative Intelligent Power Switch: several design solutions have been developed at architectural and circuital level, integrating on-chip selfdiagnostic capabilities and full protection against high voltage and reverse polarity, effects of wiring parasitics, over-current and over-temperature phenomena. Moreover current slope and soft start integrated techniques has ensured low EMI, making the Intelligent Power Switch also configurable to drive different interchangeable loads efficiently. The innovative device proposed has been implemented in a 0.35 μm HV-CMOS technology and embedded in mechatronic 3rd generation brush-holder regulator System-on-Chip for an automotive alternator. Electrical simulations and experimental characterization and testing at componentlevel and on-board system-level has proven that the proposed design allows for a compact and smart power switch realization, facing the harshest automotive conditions. The smart driver has been able to supply up to 1.5 A to various types of loads (e.g.: incadescent lamp bulbs, LED), in operating temperatures in the wide range -40 °C to 150 °C, with robustness against high voltage up to 55 V and reverse polarity up to -15 V. The second branch of research activity has been framed within the High Energy Physics area, leading to the development of a general purpose and flexible protocol for the data acquisition and the distribution of Timing, Trigger and Control signals and its implementation in radiation tolerant interfaces in CMOS 130 nm technology. The several features integrated in the protocol has made it suitable for different High Energy Physics experiments: flexibility w.r.t. bandwidth and latency requirements, robustness of critical information against radiation-induced errors, compatibility with different data types, flexibility w.r.t the architecture of the control and readout systems, are the key features of this novel protocol. Innovative radiation hardening techniques have been studied and implemented in the test-chip to ensure the proper functioning in operating environments with a high level of radiation, such as the Large Hadron Collider at CERN in Geneva. An FPGA-based emulator has been developed and, in a first phase, employed for functional validation of the protocol. In a second step, the emulator has been modified as test-bed to assess the Transmitter and Receiver interfaces embedded on the test-chip. An extensive phase of tests has proven the functioning of the interfaces at the three speed options, 4xF, 8xF and 16xF (F = reference clock frequency) in different configurations. Finally, irradiation tests has been performed at CERN X-rays irradiation facility, bearing out the proper behaviour of the interfaces up to 40 Mrad(SiO2)

Instrumentation and Controls Division Progress Report for the Period July 1, 1994, to December 31, 1997: Working Together on New Horizons

The ORNL I&C Division was created to support DOE-funded research. We have since broadened our mission to include other sponsors as the need for our services has grown. This report summarizes some of the work we have been conducting on behalf of DOE, other federal agencies, and the private sector during the past three and a half years. Because we take on nearly 750 individual projects every year, much of our work cannot be reported in detail. We hope that these summaries are of interest and demonstrate that our work, rooted in DOE scientific and technological programs, can also benefit the nation, its industry, and its citizens in direct and tangible ways

Experimental Evaluation and Analysis of LED Illumination Source for Endoscopy Imaging

The minimally invasive surgery uses a small instrument with camera and light to fit the tiny cut in the skin. The selection of the light depends on the power and driving current of the circuit. It can also help in the standardization of the camera and capture the tissues' true-colour image. This paper presents the LED source analysis used in the clinical endoscopes for surgery and the human body's medical examination. Initially, a LED source selection mechanism generating intense illuminance in a visible band is proposed. A low-cost prototype model is developed to analyze the wavelength and illuminance of three different LEDs types. An effect on variation in LED illumination is investigated by changing the distance between the Borescope and LED source. True-colour image generation and tissue contrast are more important in medical diagnostics. Therefore, a sigmoid function improving the whole contrast ratio of the captured image in real-time is presented. The results of spectrum and wavelength for a current variation are presented. Type 3 LED produces higher illumination (i.e., 395 Klux) and peak wavelength (i.e., 622.05 nm) than other LEDs, while type-2 LED has better FWHM for the blue colour spectrum. The modification in the sigmoid function enhances the image with 34.25 peak PSNR producing a true-colour image

Simplified Daylight Spectrum Approximation by Blending Two Light Emitting Diode Sources

Energy-conscious facility designs strive to include natural daylight in workspaces. To improve the efficiency of illumination, significant efforts are underway to adopt more efficient light emitting diode (LED) lamps and to effectively integrate daylight with active dimming of electric lighting. However, the correlated color temperature (CCT) and spectral content of daylight varies throughout the day while existing electric light sources produce light with a fixed CCT, resulting in mixed-illumination environments. The color rendering requirements for a lamp that permits the selection of color temperature across a significant portion of the daylight locus is explored. The analysis indicates that it is possible to form a lamp having only two independently controllable groups of narrowband emitters that is capable of producing light that achieves a nearly colorimetric match to daylight from 4000-10,000K. A prototype LED lamp, with a simple control and novel drive scheme, which produces white light over a range of CCTs by blending light from a pair of sources, each with numerous, tuned LED emitters, is demonstrated. The prototype validates the lamp concept -- producing light over a broad range of CCT values (4000-8000K) while maintaining a stable color quality rendering score without requiring computations for spectral approximation once employed