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Modeling Optimization And Comparison Of Hybrid Resonant Switched Capacitor Dc Dc Converters
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Book Synopsis Modeling, Optimization, and Comparison of Hybrid Resonant Switched Capacitor DC-DC Converters by : Muhammad Hassan Kiani
Download or read book Modeling, Optimization, and Comparison of Hybrid Resonant Switched Capacitor DC-DC Converters written by Muhammad Hassan Kiani and published by . This book was released on 2018 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent decades have seen rapid growth in portable-embedded computing and communications, which in turn has accelerated the need for high performance power management and delivery. This translates to a demand for high power density, low cost, small size, and high efficiency DC-DC converters. Traditionally, magnetics-based designs (like buck or boost) have dominated the DC-DC conversion realm. However, these architectures have a tradeoff between size of passives and efficiency. Hybrid-resonant switched capacitor (ReSC) DC-DC converters have shown great potential for applications that require both high density and efficiency. These approaches are known to benefit from the favorable active-device-utilization properties of switched capacitor (SC) converters and the relatively high energy density of capacitors compared to inductors, while mitigating the charge-sharing losses inherent in SC designs. Compared to buck or boost DC-DC converters the hybrid approach promises to reduce the size of magnetic components by reducing the volt-second or flux linkage requirements. While hybrid-resonant SC converters have shown a lot of promise, it has thus far been difficult to assess which topologies are most favorable given constraints on size (area or volume), energy storage, or power loss. This work presents a comprehensive study to model the losses in hybrid-resonant switched capacitor (ReSC) DC-DC converters. Both the losses in the active semiconductor devices and magnetic components are considered. The formulation presented in this work allows comparison between different converter architectures across conversion ratios given some common constraints. Optimization techniques are presented to minimize the losses in the individual components and the overall converter. Finally, given the drive for miniaturization of passive components, a technique is developed that leads to optimal allocation of size between flying capacitors and inductor(s) with a constraint on total size of passives.
Book Synopsis Integrated Hybrid Resonant DCDC Converters by : Peter Renz
Download or read book Integrated Hybrid Resonant DCDC Converters written by Peter Renz and published by Springer Nature. This book was released on 2020-12-29 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive, single-source on resonant switched-capacitor converters. It is written in the style of a handbook, with systematic guidelines, and includes implementation examples. The authors explore integrated hybrid resonant DCDC converters in order to achieve highly compact, energy efficient and cost-effective power management solutions in the growing fields of wearables and internet-of-things applications. They provide an introduction into hybrid converters as a new and promising converter class, which merges capacitive and inductive conversion concepts into one. Coverage ranges from fundamentals to implementation details, including topics such as power stage design, gate drive schemes, different control mechanisms for resonant operation and integrated passives. Introduces a new, multi-ratio resonant converter architecture, which enables lower switching frequencies and better passive component utilization; Discusses circuit block design for high efficiency of the power stage; Explores implementation details and concepts for integrated passives; Derives models, implements and compares to each other different control mechanisms.
Book Synopsis Advanced Multiphasing Switched-Capacitor DC-DC Converters by : Nicolas Butzen
Download or read book Advanced Multiphasing Switched-Capacitor DC-DC Converters written by Nicolas Butzen and published by Springer Nature. This book was released on 2020-07-03 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gives a detailed analysis of switched-capacitor DC-DC converters that are entirely integrated on a single chip and establishes that these converters are mainly limited by the large parasitic coupling, the low capacitor energy density, and the fact that switched-capacitor converter topologies only have a fixed voltage conversion ratio. The authors introduce the concept of Advanced Multiphasing as a way to circumvent these limitations by having multiple out-of-phase parallel converter cores interact with each other to minimize capacitor charging losses, leading to several techniques that demonstrate record efficiency and power-density, and even a fundamentally new type of switched-capacitor topology that has a continuously-scalable conversion ratio. Provides single-source reference to the recently-developed Advanced Multiphasing concept; Enables greatly improved performance and capabilities in fully integrated switched-capacitor converters; Enables readers to design DC-DC converters, where multiple converter cores are put in parallel and actively interact with each other over several phases to improve their capabilities.
Book Synopsis Analysis and Design Optimization of Resonant DC-DC Converters by : Xiang Fang
Download or read book Analysis and Design Optimization of Resonant DC-DC Converters written by Xiang Fang and published by . This book was released on 2012 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development in power conversion technology is in constant demand of high power efficiency and high power density. The DC-DC power conversion is an indispensable stage for numerous power supplies and energy related applications. Particularly, in PV micro-inverters and front-end converter of power supplies, great challenges are imposed on the power performances of the DC-DC converter stage, which not only require high efficiency and density but also the capability to regulate a wide variation range of input voltage and load conditions. The resonant DC-DC converters are good candidates to meet these challenges with the advantages of achieving soft switching and low EMI. Among various resonant converter topologies, the LLC converter is very attractive for its wide gain range and providing ZVS for switches from full load to zero load condition. The operation of the LLC converter is complicated due to its multiple resonant stage mechanism. A literature review of different analysis methods are presented, and it shows that the study on the LLC is still incomplete. Therefore, an operation mode analysis method is proposed, which divides the operation into six major modes based on the occurrence of resonant stages. The resonant currents, voltages and the DC gain characteristics for each mode is investigated. To obtain a thorough view of the converter behavior, the boundaries of every mode are studied, and mode distribution regarding the gain, load and frequency is presented and discussed. As this operation mode model is a precise model, an experimental prototype is designed and built to demonstrate its accuracy in operation waveforms and gain prediction. Since most of the LLC modes have no closed-form solutions, simplification is necessary in order to utilize this mode model in practical design. Some prior approximation methods for converter's gain characteristics are discussed. Instead of getting an entire gain-vs.-frequency curve, we focus on peak gains, which is an important design parameters indicating the LLC's operating limit of input voltage and switching frequency. A numerical peak gain approximation method is developed, which provide a direct way to calculate the peak gain and its corresponding load and frequency condition. The approximated results are compared with experiments and simulations, and are proved to be accurate. In addition, as PO mode is the most favorable operation mode of the LLC, its operation region is investigated and an approximation approach is developed to determine its boundary. The design optimization of the LLC has always been a difficult problem as there are many parameters affecting the design and it lacks clear design guidance in selecting the optimal resonant tank parameters. Based on the operation mode model, three optimization methods are proposed according to the design scenarios. These methods focus on minimize the conduction loss of resonant tank while maintaining the required voltage gain level, and the approximations of peak gains and PO mode boundary can be applied here to facilitate the design. A design example is presented using one of the proposed optimization methods. As a comparison, the L-C component values are reselected and tested for the same design specifications. The experiments show that the optimal design has better efficiency performance. Finally, a generalized approach for resonant converter analysis is developed. It can be implemented by computer programs or numerical analysis tools to derive the operation waveforms and DC characteristics of resonant converters.
Book Synopsis Integrated High-Vin Multi-MHz Converters by : Jürgen Wittmann
Download or read book Integrated High-Vin Multi-MHz Converters written by Jürgen Wittmann and published by Springer Nature. This book was released on 2019-09-03 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides readers with guidelines for designing integrated multi-MHz-switching converters for input voltages/system supplies up to 50V or higher. Coverage includes converter theory, converter architectures, circuit design, efficiency, sizing of passives, technology aspects, etc. The author discusses new circuit designs, new architectures and new switching concepts, including dead-time control and soft-switching techniques that overcome current limitations of these converters. The discussion includes technology related issues and helps readers to choose the right technology for fast-switching converters. This book discusses benefits and drawbacks in terms of integration, size and cost, efficiency and complexity, and enables readers to make trade-offs in design, given different converter parameters. Describes a study for increasing switching frequencies up to 30 MHz at input voltages up to 50V or higher in the scaling of the size of switching converter passives; Analyzes various buck converter implementations and shows that a preference due to higher efficiency depends on the operating point, on the available switch technologies, and on the implementation of the high-side supply generation; Describes an efficiency model based on a four-phase model, which enables separation of loss causes and loss locations.
Book Synopsis Optimization and Application of Switched-capacitor DC-DC Converters to SRAM by : Kyoohyun Noh
Download or read book Optimization and Application of Switched-capacitor DC-DC Converters to SRAM written by Kyoohyun Noh and published by . This book was released on 2010 with total page 75 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Synchronous and Resonant DC/DC Conversion Technology, Energy Factor, and Mathematical Modeling by : Fang Lin Luo
Download or read book Synchronous and Resonant DC/DC Conversion Technology, Energy Factor, and Mathematical Modeling written by Fang Lin Luo and published by CRC Press. This book was released on 2018-10-03 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numbers alone are enough to describe the importance of DC/DC converters in modern power engineering. There are more than 500 recognized topologies, with more added each year. In their groundbreaking book Advanced DC/DC Converters, expert researchers Luo and Ye organized these technologies into six generations and illustrated their principles and operation through examples of over 100 original topologies. In chapters carefully drawn from that work, Synchronous and Resonant DC/DC Conversion Technology, Energy Factor, and Mathematical Modeling provides a focused, concise overview of synchronous and multiple-element resonant power converters. This reference carefully examines the topologies of more than 50 synchronous and resonant converters by illustrating the design of several prototypes developed by the authors. Using more than 100 diagrams as illustration, the book supplies insight into the fundamental concepts, design, and applications of the fifth (synchronous) and sixth (multiple-element resonant) converters as well as DC power sources and control circuits. The authors also discuss EMI/EMC problems and include a new chapter that introduces the new concept of Energy Factor (EF) and its importance in mathematical modeling as well as analyzing the transient process and impulse response of DC/DC converters. Synchronous and Resonant DC/DC Conversion Technology, Energy Factor, and Mathematical Modeling supplies a quick and accessible guide for anyone in need of specialized information on synchronous and resonant DC/DC converter technologies.
Book Synopsis Hybrid Switched-capacitor Power Converter Techniques by : Nathan Miles Ellis
Download or read book Hybrid Switched-capacitor Power Converter Techniques written by Nathan Miles Ellis and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Power conversion is a necessity in almost all modern electric systems and machines: energy must be regulated and delivered in the intended manner if a system is to perform well, or at all. Power converters, the electronic circuits used to control this energy flow, have been a subject of intense study and rapid development in recent years and are widely acknowledged to be a fundamental enabler for modern day human societal capabilities. Many market sectors have strongly advocated for further development of energy conversion systems with improved efficiency and power density as these traits often directly dictate practical viability. While advancements in semiconductor device physics have yielded improved parts for use inconverter solutions, it is becoming apparent that there is additional massive potential and merit in revisiting fundamental converter topologies and circuit techniques. To date, power converters that use capacitors as their primary energy transfer elements (termed "switchedcapacitor" power converters) are far less ubiquitous than their switched-inductor counterparts, and seemingly for good reason: characteristics such as poor output regulation and intrinsic transient inrush currents that lead to inefficiency have largely prevented switched-capacitor topologies from gaining practical consideration in general power converter markets. Solutions to these negative attributes are strongly desired as capacitors can offer energy densities up to three orders of magnitude greater than inductors, with these energy transfer elements typically consuming the majority of a power converter's weight/volume. Recent work has demonstrated significant potential for hybrid switched-capacitor-inductor converter techniques: here, small inductive element(s) are used to eliminate the conventional drawbacks of a converter which is predominantly capacitor based. The hybridized approach helps unlock the full potential of capacitor-based converters and has been demonstrated to offer compelling results at the cost of added complexity. This work offers an exploration into a collection of state-of-the-art power converter techniques and topological methods, primarily within the field of hybridized switched-capacitor-inductor converters. The first two chapters give a background on fundamental considerations such as conventional loss mechanisms and the slow-switching-limit (SSL), as well as several established loss mitigation techniques. An integrated converter system and its associated functional blocks is then discussed in Chapters 3 and 4, exemplifying a hybridized two-stage converter and illustrating the implementation of several loss mitigation methods and practical circuit techniques. Next, several hybridized variations of the Dickson topology are discussed: this family of DC-DC converters is well suited for non-isolated large voltage conversion ratios. A number of these variants are proposed here for the first time, illustrating significant potential for further converter development. The steady-state bias points, resonant switching frequency, duty cycle and voltage ripple as a function of load are calculated for several example converters, including the non-trivial case of a converter undergoing split-phase operation and whose operating points exhibit a strong load dependence. To facilitate comparative analysis between topologies, a mathematical method is presented that characterizes the total energy density utilization of fly capacitors throughout a converter, accounting for large voltage ripple and iii highly nonlinear reverse-bias transitions. This analysis assists with optimal topology selection as energy density utilization directly dictates the required capacitor volume at a specified power level and switching frequency. An expanded family of fly capacitor networks is then introduced in Chapter 6; here it is shown that there are a large number of unexplored yet practical fly capacitor configurations that are eligible for use in hybridized converters. It is calculated that a 6-7 % reduction in capacitor volume can be achieved relative to conventional Dickson fly capacitor networks, while preserving the desirable characteristic of equal voltage ripple on its branches. N-phase and split-phase switching methods and their respective trade-offs are then discussed in detail, offering control techniques that allow a departure from conventional two-phase operation while retaining high-efficiency zero-voltage and zero-current switching (ZVS/ZCS) conditions. A Cockcroft-Walton prototype demonstrates both methods implemented on the same piece of hardware, significantly improving the efficiency range with respect to load and resulting in a state-of-the-art power density of 483.3 kW/liter (7, 920W/inch3). Next, a method termed "resonant charge redistribution" (RCR) is proposed that greatly reduces output capacitance (C[subscript OSS]) related switching losses in all switches of a complex switched-capacitor network. Despite little effort being put towards optimization, a prototype using RCR measures a 61 % reduction in total losses at light load for a near negligible 0.74 % increase in total solution volume. Lastly, resonant gate drive techniques are discussed. Here, within a proposed resonant gate-driver topology, a capacitive decoupling technique is demonstrated that allows power to be delivered to a "flying" high-side N-channel device which commutes between two variable voltages. The implemented prototype achieves up to a 72 % reduction in gating loss when switching over 20 MHz and with rise/fall times ≤ 7 ns. Combining several of the novel techniques described herein can result in near complete mitigation of all primary switching loss mechanisms observed throughout the complex structure of a switched-capacitor converter network. This relatively new field of hybridized converter design has already yielded converters with record-breaking performance, as is demonstrated here. With contemporary techniques, including those described in this work, the field of power electronics is on the cusp of seeing widespread dramatic improvements in energy handling capability, power density, specific power and efficiency at reduced cost, with huge potential for growth and improved energy consumption in both developed and emerging markets.
Book Synopsis Equivalent-Small-Parameter Analysis of DC/DC Switched-Mode Converter by : Yanfeng Chen
Download or read book Equivalent-Small-Parameter Analysis of DC/DC Switched-Mode Converter written by Yanfeng Chen and published by Springer. This book was released on 2018-10-06 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the applications of Equivalent-Small-Parameter Method (ESPM) in solving the steady-state periodic solutions, as well as stability analysis, of kinds of open-loop or closed-loop operated DC/DC converters, such as PWM, quasi-resonant and resonant ones. The analytical expressions of DC components and harmonics of state variables (inductor current and capacitor voltage) with DC/DC converters can be obtained by ESPM, which can be helpful to understand the nonlinear operating mechanism of switched-mode converters. It can also be useful for stability analysis and design for practical converters. Modeling and analysis on all kinds of DC/DC converters are introduced in detail in this book, along with a large amount of simulation or experimental waveforms to verify the correctness of the theoretical analysis based on ESPM.
Book Synopsis Topologies, Modeling, and Control of Hybrid Switched-Capacitor Converters by : Ratul Das
Download or read book Topologies, Modeling, and Control of Hybrid Switched-Capacitor Converters written by Ratul Das and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation explored the ideas and concepts for hybrid switched capacitor converter topologies and new power delivery architectures to provide viable solutions for high conversion ratio DC-DC and AC-DC applications. A new Multi Inductor Hybrid (MIH) Converter family for high conversion ratio DC-DC applications has been synthesized and analyzed to provide non-isolated DC-DC conversions with large voltage conversion ratios efficiently. The highlight of this converter family is a 6-level 6-phase 6-inductor MPMIH converter, which achieved 90.7% peak efficiency with a load range of 0-220A at 1V and 1kA/in3 density. A new modeling method reveals that all odd-level Flying Capacitor Multi-Level converters become current sources with non-ideal timing while the even-level converters stay as voltage sources. A method for identifying unbalanced hybrid converters is also provided. This dissertation demonstrates a two-stage power delivery architecture to bridge AC distribution voltages to core levels for computing loads in data centers. In combination, direct conversion from ~110 VAC to 1VDC achieves a peak efficiency of 84.1% while providing output currents up to 160A. Partial power processing for AC/DC applications has been explored with a switched-capacitor (SC) based hybrid step-down converter and its new control techniques. The operation with multiple modules is verified with a 115VAC-to-48VDC conversion and 200VAC input to two 48VDC outputs. A new modular isolated DC-DC converter is proposed and demonstrated for point-pf-load (POL) applications with partial power processing. A prototype of the modular architecture has been demonstrated for a 100V-to-3V point-of-load conversion with a maximum load of 60A. The peak efficiency of 91% is achieved at 57W/20A output. A new multi-inductor multi-output hybrid converter is also proposed and demonstrated. The MiMoH converter prototype has been implemented to demonstrate conversion from a 24-48V input voltage to three individually regulated outputs ranging from 1.2V to 2.2V. The converter prototype achieves 40W peak power and 91.8% peak efficiency. The topologies presented in this dissertation, corroborated with control and modeling techniques, demonstrated superior performance, natural balancing ability, and relatively easy controllability, making them excellent candidates for more compact and efficient system design.
Book Synopsis Multi-Objective Optimization of Unidirectional Non-Isolated DC/DC Converters by : Andrija Stupar
Download or read book Multi-Objective Optimization of Unidirectional Non-Isolated DC/DC Converters written by Andrija Stupar and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Engineers have to fulfill multiple requirements and strive towards often competing goals while designing power electronic systems. This can be an analytically complex and computationally intensive task since the relationship between the parameters of a system's design space is not always obvious. Furthermore, a number of possible solutions to a particular problem may exist. To find an optimal system, many different possible designs must be evaluated. Literature on power electronics optimization focuses on the modeling and design of particular converters, with little thought given to the mathematical formulation of the optimization problem. Therefore, converter optimization has generally been a slow process, with exhaustive search, the execution time of which is exponential in the number of design variables, the prevalent approach. In this thesis, geometric programming (GP), a type of convex optimization, the execution time of which is polynomial in the number of design variables, is proposed and demonstrated as an efficient and comprehensive framework for the multi-objective optimization of non-isolated unidirectional DC/DC converters. A GP model of multilevel flying capacitor step-down converters is developed and experimentally verified on a 15-to-3.3~V, 9.9~W discrete prototype, with sets of loss-volume Pareto optimal designs generated in under one minute. It is also demonstrated how the GP model can be used to determine the sensitivity of the optimized designs to the design parameters. Furthermore, a general procedure for deriving GP models is presented and demonstrated on the example of inductors for higher power applications. Finally, using the example of the seven-switch flying capacitor converter, it is shown how in cases where a converter-level GP model is not possible, component-level GP models can be coupled with a circuit simulator to perform efficiency optimization quickly. This hybrid approach is used to design a wide input and output voltage range, 2~A output current converter IC. The results show that GP is of great value to both researchers and practicing engineers. The methods demonstrated for deriving GP models of power converters are extendable to other converter topologies, allowing for the creation of a rigorous mathematical framework for the optimization of power electronics that guarantees globally optimum designs generated quickly.
Book Synopsis Enhanced-performance Integrated Resonant Switched-Capacitor and Buck DC-DC Converters for Application in Extreme Radiation and Magnetic Field Environments by : Giacomo Ripamonti
Download or read book Enhanced-performance Integrated Resonant Switched-Capacitor and Buck DC-DC Converters for Application in Extreme Radiation and Magnetic Field Environments written by Giacomo Ripamonti and published by . This book was released on 2020 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mots-clés de l'auteur: DC-DC converters ; resonant power conversion ; integrated circuits ; modeling ; radiation hardening.
Book Synopsis On-chip Buck-boost Switched-capacitor DC-DC Converter by : Chaohao Wang
Download or read book On-chip Buck-boost Switched-capacitor DC-DC Converter written by Chaohao Wang and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The increasing integration level of CMOS integrated circuits (ICs) poses significant challenges for the power delivery network. Multiple independent power domains, each of them individually adjustable, are desirable for complex ICs to optimize the tradeoff between performance and energy consumption. A two-stage power management system, in which a first-stage global converter with a large down conversion ratio is followed by multiple second-stage local regulators for different power domains, fits well in modern power delivery networks. The first stage can be built with conventional, fully optimized DC-DC converters, while the second stage requires flexible, high-density, and high-efficiency on-chip DC-DC converters. With the enhanced fabrication capability of high-density on-chip capacitors, the switched-capacitor (SC) DC-DC converter becomes a perfect candidate for these second-stage on-chip regulators. This dissertation presents the architecture, modeling and design techniques for the development of fully integrated on-chip SC DC-DC converters for the purpose of local regulation. The proposed converter can step up or down the voltage based on the output requirement and circuit performance. Using the unit cell array approach, conversion ratios of n/(n+1) with buck configurations and (n+1)/n with boost configurations are achievable when n cells are grouped as a single converter. Thus, adequate topologies exist to provide a large range of output voltage with high efficiency. A prototype chip with 204 unit cells and nine different finely spaced buck and boost topologies was designed and fabricated in a 45nm bulk CMOS technology. The input is 1V, and the output ranges from 0.58V to 1.3V. The SC converter achieves a peak efficiency of 82.2% at a maximum power density of 0.16W/mm2. Furthermore, the efficiency varies by only 4.2% over the output voltage range. A digital algorithm for closed loop control was implemented in a field-programmable gate array (FPGA) to demonstrate that performance regulation using this type of converter can match circuit performance requirements and compensate for operating conditions or process variations. This dissertation also projects the potential improvements in SC converters with more advanced technology nodes as well as capacitor density scaling, such as using special on-chip capacitor processes like Metal-Insulator-Metal (MIM) capacitors and deep trench capacitors.
Book Synopsis Analytical and Practical Analysis of Switched-capacitor DC-DC Converters by : Michael Douglas Seeman
Download or read book Analytical and Practical Analysis of Switched-capacitor DC-DC Converters written by Michael Douglas Seeman and published by . This book was released on 2006 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Resonant and Multi-mode Operation of Inductive Switched Capacitor Converters by : Kapil Kesarwani
Download or read book Resonant and Multi-mode Operation of Inductive Switched Capacitor Converters written by Kapil Kesarwani and published by . This book was released on 2015 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: While efficiency has always been an important metric for power electronics, power density is growing in importance as driven by a variety of applications including performance and mobile computing, renewable energy and automotive applications. The drive towards higher power density generally requires operation at very high frequency which allows miniaturization of passive components, especially inductors, which occupy a large fraction of the total volume. However, the aggressive scaling of frequency leads to moderate efficiency of such converters due to increase in frequency dependent losses. It is therefore desirable to explore DC-DC conversion techniques which lead to lower passive component volume at low to moderate frequencies of operation. This thesis explores resonant and multi-mode operation of inductive Switched Capacitor (SC) converters for high efficiency, high power density converters. A loss model of the resonant operation of a 2:1 indirect Resonant SC (ReSC) converter is developed and compared to the loss model of a 2:1 Switched Capacitor (SC) converter. These loss models are used to compare SC and ReSC converter classes in the efficiency versus power density space using representative passive component and process technology models. A novel technique referred to as Dynamic Off Time Modulation (DOTM) is presented. This technique allows linear scaling of the output impedance of ReSC converters which enables linear regulation of these converters and maintains peak efficiency in light load conditions. For experimental verification, an integrated circuit design based on this model is completed in a 0.18 [mu]m CMOS process and the results from this chip are presented. An alternative direct topology for performing resonant conversion is explored and its advantages over the indirect topology, discussed earlier, are presented. Experimental verification from a 24 V: 12 V converter is presented. It is shown that resonant, DOTM and non-resonant modes of operation for the direct topology improve its efficiency over a wide output current range. This multi-mode operation of the direct topology allows unification of the resonant and soft-charging approach to solve charge sharing loss problem of the SC converter. Supporting experimental results from a 24 V: 12 V converter are presented. The direct topology which is derived from a 3-level converter topology fits into the general class of inductive SC converters. It is shown that inductive SC converters can achieve regulation by addition of extra states into the converter operation. It is shown that this mode of operation leads to unconstrained flying capacitor voltage problems in a general inductive SC converter; similar to the unconstrained flying capacitor voltage problems observed in 3-level converters and therefore inductive SC converters require active control of flying capacitor voltages for safe operation. Finally, flying capacitor multi-level (FCML) converters are studied as an alternative inductive SC topology. The benefits of FCML converters over the other inductive SC topologies are discussed. Results from a 50 V to 7 V 4-level flying capacitor converter are presented. A control method to balance the flying capacitor voltages through low frequency closed loop feedback on the switching node voltage is presented. Though not discussed in detail, it can be appreciated that the multi-mode operation of inductive SC converters could also be applied to FCML converters to improve their efficiency and power density.
Book Synopsis Analysis and Design of Switched-capacitor DC-DC Converters with Discrete Event Models by : Danhui Li
Download or read book Analysis and Design of Switched-capacitor DC-DC Converters with Discrete Event Models written by Danhui Li and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis An Optimized, Variable-Gain Switched-Capacitor DC-DC Converter by : Marko Krstic
Download or read book An Optimized, Variable-Gain Switched-Capacitor DC-DC Converter written by Marko Krstic and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
