Design and Analysis of Switched-capacitor Based Partial Power Architecture for Radio Frequency DC-DC Power Conversion with Gallium Nitride Power Devices

Design and Analysis of Switched-capacitor Based Partial Power Architecture for Radio Frequency DC-DC Power Conversion with Gallium Nitride Power Devices PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 430

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Book Description
This thesis investigates a new reconfigurable switched-capacitor (SC) based partial power architecture which enhances the performance of resonant DC/DC converters operating at radio frequency (RF) with gallium nitride (GaN) power devices to address challenges in telecommunication brick DC/DC converters. The proposed architecture has a comprehensive compatibility with existing RF and SC topologies and improves the performance of RF converters through partitioning of energy conversion stage and output regulation stage. Emerging new wide bandgap devices like GaN FETs enable a higher power density DC/DC converter design. A wider input range, larger voltage conversion ratio, smaller size, and excellent transient performance are expected. The prototype of the proposed GaN reconfigurable SC-based partial power RF converter comprises of a 20 MHz resonant single-ended-primary-inductor-converter (SEPIC) as a regulated stage and a high-efficiency 2 MHz reconfigurable SC as an unregulated stage. The GaN RF resonant SEPIC regulates the output using a robust ON/OFF control scheme, which enables fast transient responses. The high-efficiency GaN reconfigurable SC provides 1:1, 2:1 and 3:1 voltage conversion ratio which widens the input voltage range. A full time-domain, closed-form analytical model for RF resonant SEPIC has been developed, and new design methodology has been proposed for the GaN reconfigurable SC to address the design challenges at megahertz. The electromagnetic interference (EMI) characteristics of the prototype have also been investigated and evaluated by experiments. An alternative control scheme and PCB layout guidelines have been developed for EMI reduction.

Design and Analysis of Switched-capacitor Based Partial Power Architecture for Radio Frequency DC-DC Power Conversion with Gallium Nitride Power Devices

Design and Analysis of Switched-capacitor Based Partial Power Architecture for Radio Frequency DC-DC Power Conversion with Gallium Nitride Power Devices PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 430

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Book Description
This thesis investigates a new reconfigurable switched-capacitor (SC) based partial power architecture which enhances the performance of resonant DC/DC converters operating at radio frequency (RF) with gallium nitride (GaN) power devices to address challenges in telecommunication brick DC/DC converters. The proposed architecture has a comprehensive compatibility with existing RF and SC topologies and improves the performance of RF converters through partitioning of energy conversion stage and output regulation stage. Emerging new wide bandgap devices like GaN FETs enable a higher power density DC/DC converter design. A wider input range, larger voltage conversion ratio, smaller size, and excellent transient performance are expected. The prototype of the proposed GaN reconfigurable SC-based partial power RF converter comprises of a 20 MHz resonant single-ended-primary-inductor-converter (SEPIC) as a regulated stage and a high-efficiency 2 MHz reconfigurable SC as an unregulated stage. The GaN RF resonant SEPIC regulates the output using a robust ON/OFF control scheme, which enables fast transient responses. The high-efficiency GaN reconfigurable SC provides 1:1, 2:1 and 3:1 voltage conversion ratio which widens the input voltage range. A full time-domain, closed-form analytical model for RF resonant SEPIC has been developed, and new design methodology has been proposed for the GaN reconfigurable SC to address the design challenges at megahertz. The electromagnetic interference (EMI) characteristics of the prototype have also been investigated and evaluated by experiments. An alternative control scheme and PCB layout guidelines have been developed for EMI reduction.

Reconfigurable Switched-Capacitor Power Converters

Reconfigurable Switched-Capacitor Power Converters PDF Author: Dongsheng Ma
Publisher: Springer Science & Business Media
ISBN: 1461441870
Category : Technology & Engineering
Languages : en
Pages : 182

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Book Description
This book provides readers specializing in ultra-low power supply design for self-powered applications an invaluable reference on reconfigurable switched capacitor power converters. Readers will benefit from a comprehensive introduction to the design of robust power supplies for energy harvesting and self-power applications, focusing on the use of reconfigurable switched capacitor based DC-DC converters, which is ideal for such applications. Coverage includes all aspects of switched capacitor power supply designs, from fundamentals, to reconfigurable power stages, and sophisticated controller designs.

Advanced Multiphasing Switched-Capacitor DC-DC Converters

Advanced Multiphasing Switched-Capacitor DC-DC Converters PDF Author: Nicolas Butzen
Publisher: Springer Nature
ISBN: 3030387356
Category : Technology & Engineering
Languages : en
Pages : 160

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Book Description
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.

Analytical and Practical Analysis of Switched-capacitor DC-DC Converters

Analytical and Practical Analysis of Switched-capacitor DC-DC Converters PDF Author: Michael Douglas Seeman
Publisher:
ISBN:
Category :
Languages : en
Pages : 116

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Book Description


Hybrid Switched-capacitor Power Converter Techniques

Hybrid Switched-capacitor Power Converter Techniques PDF Author: Nathan Miles Ellis
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
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.

Demystifying Switched Capacitor Circuits

Demystifying Switched Capacitor Circuits PDF Author: Mingliang (Michael) Liu
Publisher: Elsevier
ISBN: 0080458769
Category : Technology & Engineering
Languages : en
Pages : 332

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Book Description
This book helps engineers to grasp fundamental theories and design principles by presenting physical and intuitive explanations of switched-capacitor circuits. Numerous circuit examples are discussed and the author emphasizes the most important and fundamental principles involved in implementing state-of-the-art switched-capacitor circuits for analog signal processing and power management applications. Throughout the book, the author presents numerous step-by-step tutorials and gives practical design examples.While some quantitative analysis is necessary to understand underlying concepts, tedious mathematical equations and formal proofs are avoided. An intuitive appreciation for switched-capacitor circuits is achieved.Much of the existing information on contemporary switched-capacitor circuit applications is in the form of applications notes and data sheets for various switched-capacitor ICs. This book compiles such information in a single volume and coherently organizes and structures it.The author has his own website at www.mingliangliu.com * Step-by-step tutorials which emphasize the most fundamental principals of switched-capacitor circuits * Few tedious mathematical equations * The first easy-to-understand compilation on this subject--most information available is not very cohesive

Design of Low-Voltage CMOS Switched-Opamp Switched-Capacitor Systems

Design of Low-Voltage CMOS Switched-Opamp Switched-Capacitor Systems PDF Author: Vincent S.L. Cheung
Publisher: Springer Science & Business Media
ISBN: 1475737017
Category : Technology & Engineering
Languages : en
Pages : 207

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Book Description
This volume emphasizes the design and development of advanced switched-opamp architectures and techniques for low-voltage low-power switched-capacitor systems. It presents a novel multi-phase switched-opamp technique together with new system architectures that are critical in improving significantly the performance of switched-capacitor systems at low supply voltages.

Design and Implementation of High Frequency 3D DC-DC Converter

Design and Implementation of High Frequency 3D DC-DC Converter PDF Author: Florian Neveu
Publisher:
ISBN:
Category :
Languages : en
Pages : 218

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Book Description
Ultimate integration of power switch-mode converter relies on two research paths. One path experiments the development of switched-capacitor converters. This approach fits silicon integration but is still limited in term of power density. Inductive DC-DC architectures of converters suffer by the values and size of passive components. This limitation is addressed with an increase in frequency. Increase in switching losses in switches leads to consider advanced technological nodes. Consequently, the capability with respect to input voltage is then limited. Handling 3.3 V input voltage to deliver an output voltage in the range 0.6 V to 1.2 V appears a challenging specification for an inductive buck converter if the smallest footprint is targeted at +90 % efficiency. Smallest footprint is approached through a 3D assembly of passive components to the active silicon die. High switching frequency is also considered to shrink the values of passive components as much as possible. In the context of on-chip power supply, the silicon technology is dictated by the digital functions. Complementary Metal-Oxide- Semiconductor (CMOS) bulk C40 is selected as a study case for 3.3 V input voltage. 3.3 V Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) features poor figure of merits and 1.2 V standard core, regular devices are preferred. Moreover future integration as an on-chip power supply is more compatible. A three-MOSFET cascode arrangement is experimented and confronted experimentally to a standard buck arrangement in the same technology. The coupled-phase architecture enables to reduce the switching frequency to half the operating frequency of the passive devices. +100MHz is selected for operation of passive devices. CMOS bulk C40 offers Metal-Oxide-Metal (MOM) and MOS capacitors, in density too low to address the decoupling requirements. Capacitors have to be added externally to the silicon die but in a tight combination. Trench-cap technology is selected and capacitors are fabricated on a separate die that will act as an interposer to receive the silicon die as well as the inductors. The work delivers an object containing a one-phase buck converter with the silicon die flip-chipped on a capacitor interposer where a tiny inductor die is reported. The one-phase demonstrator is suitable for coupled-phase demonstration. Standard and cascode configurations are experimentally compared at 100 MHz and 200 MHz switching frequency. A design methodology is presented to cover a system-to-device approach. The active silicon die is the central design part as the capacitive interposer is fabricated by IPDiA and inductors are provided by Tyndall National Institute. The assembly of the converter sub-parts is achieved using an industrial process. The work details a large set of measurements to show the performances of the delivered DC/DC converters as well as its limitations. A 91.5% peak efficiency at 100MHz switching frequency has been demonstrated.

Highly Integrated Switched-mode Power Converters Employing CMOS and GaN Technologies for Distributed MPPT

Highly Integrated Switched-mode Power Converters Employing CMOS and GaN Technologies for Distributed MPPT PDF Author: Kiran Kumar Krishnan Achary
Publisher:
ISBN:
Category : Electric current converters
Languages : en
Pages : 56

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Book Description
The photovoltaic systems used to convert solar energy to electricity pose a multitude of design and implementation challenges, including energy conversion efficiency, partial shading effects, and power converter efficiency. Using power converters for Distributed Maximum Power Point Tracking (DMPPT) is a well-known architecture to significantly reduce power loss associated with mismatched panels. Sub-panel-level DMPPT is shown to have up to 14.5% more annual energy yield than panel-level DMPPT, and requires an efficient medium power converter.This research aims at implementing a highly efficient power management system at sub-panel level with focus on system cost and form-factor. Smaller form-factor motivates increased converter switching frequencies to significantly reduce the size of converter passives and substantially improve transient performance. But, currently available power MOSFETs put a constraint on the highest possible switching frequency due to increased switching losses. The solution is Gallium Nitride based power devices, which deliver figure of merit (FOM) performance at least an order of magnitude higher than existing silicon MOSFETs. Low power loss, high power density, low cost and small die sizes are few of the qualities that make e-GaN superior to its Si counterpart. With careful design, e-GaN can enable a 20-30% improvement in power stage efficiency compared to converters using Si MOSFETs. The main objective of this research is to develop a highly integrated, high efficiency, 20MHz, hybrid GaN-CMOS DC-DC MPPT converter for a 12V/5A sub-panel. Hard and soft switching boost converter topologies are investigated within this research, and an innovative CMOS gate drive technique for efficiently driving an e-GaN power stage is presented in this work. The converter controller also employs a fast converging analog MPPT control technique.

Circuit Modeling and Performance Evaluation of GaN Power HEMT in DC-DC Converters

Circuit Modeling and Performance Evaluation of GaN Power HEMT in DC-DC Converters PDF Author: Krushal S. Shah
Publisher:
ISBN:
Category : DC-to-DC converters
Languages : en
Pages : 72

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Book Description
The power generated by renewable sources such as solar photo-voltaic (PV) arrays and wind turbines is time varying and unpredictable. In order to minimize the wastage of power obtained from such sources, there is a great need of efficient power converters which are compact and can effectively manage power in Smart Grid applications. The design of such power converters would require the use of new semiconductor materials, novel device structures, improved switching and control circuits, and advanced packaging technologies. Wide bandgap materials are promising for RF/microwave and power switching electronics. Among these materials, III-V Nitrides - especially Gallium Nitride (GaN), and Silicon Carbide (SiC) are heavily investigated by industry because of their superior electrical and thermal properties, and improved radiation hardness compared to the standard semiconductor material -silicon. A smart DC microgrid suitable for high-penetration in commercial applications and that efficiently utilizes energy available from distributed, renewable generators is described. GaN HEMTs based converters should be incorporated in the DC microgrid. It iv is shown that the proposed DC power distribution system can produce savings in excess of 10-15% over the current approach that uses inverters. Performance evaluation between silicon MOSFET and GaN HEMT is presented for chip-scale and maximum peak power tracking DC-DC power converter applications. The current circuit model available for GaN HEMTs does not converge for converter topology. Thus circuit calculations are based on improved circuit model for the FET with accurate description of capacitances and thermal on-resistance. It is shown that GaN power HEMTs used in a synchronous buck converter topology (for a 19/1.2VDC, 7.2W) can potentially lead to nearly 77 % power conversion efficiency at 25°C when switched at 5 MHz. However, results show that the current formulation for loss calculation in the topology described is erroneous and so there is a need of new loss formulation and device selection criteria based on circuit dynamics and device parameters. Similarly simulations were carried out for a DC-DC boost converter topology (200/380VDC, 10kW) and it has been shown to have 93 % power conversion efficiency at 25°C when switched at 1 MHz. But using new semiconductors materials like GaN HEMT and SiC in this case causes high dv/dt stress on switch and diode during switching which may cause failure of device.