Design of Area- and Power-efficient Dual-output Switched-capacitor DC-DC Converters

Design of Area- and Power-efficient Dual-output Switched-capacitor DC-DC Converters PDF Author: Zhe Hua
Publisher:
ISBN:
Category : DC-to-DC converters
Languages : en
Pages :

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Book Description
Power management integrated circuits have found wide applications in all battery-powered electronic systems like smartphones, wireless sensors, etc., to convert a time-varying unregulated battery voltage to constant regulated DC output voltages for different internal functional blocks of the system. With the increase in the complexity of today’s electronic systems, a multiple-output power management system is desired to optimize the power consumption of each loading block such that the power dissipation of the whole system can be minimized to extend the battery run-time. Driven by the demands for high power efficiency and high area efficiency in generating multiple outputs for energy-harvesting and portable applications, the multiple-output switched-capacitor (SC) DC-DC converter is becoming a popular candidate as it does not require any costly and bulky inductor for energy storage, thereby minimizing the overall converter volume and EMI noise. Moreover, flying capacitors as energy-storage components and power transistors as energy-transfer paths in the multiple-output SC DC-DC converters can be shared by different outputs such that the number of required flying capacitors and power transistors can be minimized to optimize both area efficiency and energy density. In the first part of this research, a reconfigurable step-up dual-output SC DC-DC regulator is introduced, analyzed and verified for low power energy-harvesting applications. A sub-harmonic adaptive-on-time (SHAOT) control scheme is proposed to improve the light-load power efficiency under different load currents, maintain low output ripples under different input voltages, provide predictable output noise spectrum, and minimize output cross regulation between both outputs in the SC DC-DC regulator. In the second part of this research, a battery-connected reconfigurable step-down dual-output SC DC-DC regulator is developed to deliver a maximum load of 1.2A for portable applications. With flying-capacitor sharing and an all-nMOS power stage, the proposed dual-output SC power stage is efficient in both chip and board areas. A switch-resistance-modulation (SRM) control scheme is also proposed to provide small output voltage ripples with a small load capacitance under 100s-of-mA load and to minimize output cross regulation between two outputs under large load-step variations.

Design of Area- and Power-efficient Dual-output Switched-capacitor DC-DC Converters

Design of Area- and Power-efficient Dual-output Switched-capacitor DC-DC Converters PDF Author: Zhe Hua
Publisher:
ISBN:
Category : DC-to-DC converters
Languages : en
Pages :

Get Book Here

Book Description
Power management integrated circuits have found wide applications in all battery-powered electronic systems like smartphones, wireless sensors, etc., to convert a time-varying unregulated battery voltage to constant regulated DC output voltages for different internal functional blocks of the system. With the increase in the complexity of today’s electronic systems, a multiple-output power management system is desired to optimize the power consumption of each loading block such that the power dissipation of the whole system can be minimized to extend the battery run-time. Driven by the demands for high power efficiency and high area efficiency in generating multiple outputs for energy-harvesting and portable applications, the multiple-output switched-capacitor (SC) DC-DC converter is becoming a popular candidate as it does not require any costly and bulky inductor for energy storage, thereby minimizing the overall converter volume and EMI noise. Moreover, flying capacitors as energy-storage components and power transistors as energy-transfer paths in the multiple-output SC DC-DC converters can be shared by different outputs such that the number of required flying capacitors and power transistors can be minimized to optimize both area efficiency and energy density. In the first part of this research, a reconfigurable step-up dual-output SC DC-DC regulator is introduced, analyzed and verified for low power energy-harvesting applications. A sub-harmonic adaptive-on-time (SHAOT) control scheme is proposed to improve the light-load power efficiency under different load currents, maintain low output ripples under different input voltages, provide predictable output noise spectrum, and minimize output cross regulation between both outputs in the SC DC-DC regulator. In the second part of this research, a battery-connected reconfigurable step-down dual-output SC DC-DC regulator is developed to deliver a maximum load of 1.2A for portable applications. With flying-capacitor sharing and an all-nMOS power stage, the proposed dual-output SC power stage is efficient in both chip and board areas. A switch-resistance-modulation (SRM) control scheme is also proposed to provide small output voltage ripples with a small load capacitance under 100s-of-mA load and to minimize output cross regulation between two outputs under large load-step variations.

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.

Power Systems-On-Chip

Power Systems-On-Chip PDF Author: Bruno Allard
Publisher: John Wiley & Sons
ISBN: 1119377684
Category : Science
Languages : en
Pages : 346

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Book Description
The book gathers the major issues involved in the practical design of Power Management solutions in wireless products as Internet-of-things. Presentation is not about state-of-the-art but about appropriation of validated recent technologies by practicing engineers. The book delivers insights on major trade-offs and a presentation of examples as a cookbook. The content is segmented in chapters to make access easier for the lay-person.

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.

Switched-capacitor DC-DC Converters for Near-threshold Design

Switched-capacitor DC-DC Converters for Near-threshold Design PDF Author: Moataz Abdelfattah
Publisher:
ISBN:
Category : DC-to-DC converters
Languages : en
Pages :

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Book Description
With the increasing power and thermal limits in the computing industry, energy-efficient computing has become an urging necessity. Therefore, a surge of interest has been recently given to the concept of Near-Threshold Computing (NTC) as a potential candidate to realize energy-efficiency in computations. By operating at supply voltages near the transistor’s threshold voltage, NTC promises significant energy savings with moderate performance loss, which can be compensated for through parallelism. However, NTC faces a few challenges that hinder its wide adoption. On top of these challenges are the harsh specifications required for the power management and delivery units. Specifically, a power converter in an NTC system is required to achieve high efficiency at high current densities and low output voltages while seamlessly integrated on-chip, which are all contradicting specifications. To tackle the problem of energy-efficient computing, this research work addresses the challenges of NTC, with focus on power delivery. To do so, first, the target application of NTC is investigated to acquire the basic understanding of its challenges, opening doors for innovations and solutions for these challenges. Based on this understanding, which reveals the importance of power delivery for NTC and defines the requirements on power converters, most of the work in this thesis will focus on Switched-Capacitor (SC) power converters, which are found to be the most suitable type of converters for NTC. Therefore, a detailed study and literature review of SC converters is carried out. This study provides an in-depth understanding of SC converters operation, mechanisms, and challenges. Specifically, it is demonstrated that the most advantageous characteristic of SC converters is their compatibility with CMOS integration, while the most challenging aspect is their limited current density. Consequently, this thesis sets forth to address this challenge and proposes two solutions to boost the current density of SC converters, and thus, offering feasible power converter architectures for NTC. The first solution proposed in this thesis focuses on the control loop of SC converters. Unlike regular control loops, which often utilize frequency, capacitance, or conductance modulation, the proposed technique combines all three control knobs. The combination of these parameters allows for ripple reduction without sacrificing current density, and thus, effectively increases the converter’s density. Furthermore, this combination of parameters maintains the efficiency near its peak across a wide range of load currents, which is another relevant feature for NTC. The second solution introduces the concept of resonant gate drivers to SC converters, increasing the converter efficiency with no impact on current density. This solution is implemented in 45 nm SOI technology and fabricated for validation. The measurement results demonstrate a 70% efficiency at 1 A/mm2 current density and 0.4 V output voltage, which is a new efficiency/current-density record in the near-threshold range. In summary, as a potential solution to the problem of energy-efficiency in computations, NTC and its challenges are investigated. To address its most critical challenge of power delivery, SC converters are studied and circuit techniques are proposed to boost their current density and offer a feasible power delivery for NTC applications.

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

Fully Integrated Switched-Capacitor PMU for IoT Nodes

Fully Integrated Switched-Capacitor PMU for IoT Nodes PDF Author: Ricardo Madeira
Publisher: Springer Nature
ISBN: 3031147014
Category : Technology & Engineering
Languages : en
Pages : 174

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Book Description
This book provides a step-by-step methodology and system design that can be used to design a fully integrated PMU using SC DC-DC converters, for any CMOS technology. The authors discuss trade-offs between power density and efficiency of the methodology for the 130 nm CMOS technology, and how to implement it on other CMOS technologies. The book describes the state-of-the-art of fully or near-fully integrated SC DC-DC converters with multiple conversion ratios and the techniques used to enhance the overall performance of these converters. Coverage includes the trade-off between the number of conversion ratios and overall extracted efficiency from a supercapacitor, as well as the sizing of the converter cells according to the desired output power and maximum clock frequency. The authors also describe in detail the design of the fundamental blocks for the converter operation, which includes a secondary control loop using capacitance modulation by sensing the clock frequency.

Design Techniques for Fully Integrated Switched-Capacitor Voltage Regulators

Design Techniques for Fully Integrated Switched-Capacitor Voltage Regulators PDF Author: HANH-PHUC LE
Publisher:
ISBN:
Category :
Languages : en
Pages : 77

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Book Description
As parallelism increases the number of cores integrated onto a chip, there is a clear need for fully integrated DC-DC converters to enable efficient on-die power management. Due to the availability of high density and low series resistance capacitors in existing CMOS processes, switched-capacitor DC-DC converters have recently gained significant interest as a cost-effective means of enabling such power management functionality. In this thesis, described are design techniques to implement fully integrated switched-capacitor DC-DC converters with high power density and efficiency. The area required by a fully integrated switched-capacitor DC-DC converter in order to deliver a certain level of power to the load has direct implications on both cost and efficiency, and hence in Chapter 2 a methodology is presented to predict and minimize the losses of such a converter operating at a given power density. Chapter 3 further introduces gate driver and level shifter circuit design strategies to enable topology reconfiguration and hence efficient generation of a wider range of output voltages. In order to demonstrate the possibility of replacing all off-chip PMICs, Chapter 4 presents a battery-connected switched-capacitor DC-DC converter that is able to convert the wide input voltage range from Li-ion battery to an output regulated at ~1V using cascode switches and intermediate voltage rails. The SC converter in Chapter 4 also employs a fast control loop to regulate the output with sub-ns response times. Measured results from the converters presented in Chapters 3 and 4 match with the analytical prediction and, thus, confirm the design methodology presented in Chapter 2. The 32nm SOI prototype presented in Chapter 3 achieves ~80% efficiency at a power density of ~0.5-1W/mm2 for a 2:1 step-down converter operating from a 2V input and utilizing only standard MOS capacitors. Reconfiguration of the converter's topology enables it to maintain greater than 70% efficiency for most of the output voltage range from 0.7V to ~1.15V. The 65nm Bulk CMOS prototype discussed in Chapter 4 also utilizes only standard MOS capacitors to regulate the output voltage at ~1V from a ~2.9V-4V input. It achieves ~73% efficiency at 0.19 W/mm2 output power density and maintain efficiency above 72% over the whole range of target power density. The sub-ns response control loop maintains

High-Ratio Voltage Conversion in CMOS for Efficient Mains-Connected Standby

High-Ratio Voltage Conversion in CMOS for Efficient Mains-Connected Standby PDF Author: Hans Meyvaert
Publisher: Springer
ISBN: 3319312073
Category : Technology & Engineering
Languages : en
Pages : 161

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Book Description
This book describes synergetic innovation opportunities offered by combining the field of power conversion with the field of integrated circuit (IC) design. The authors demonstrate how integrating circuits enables increased operation frequency, which can be exploited in power converters to reduce drastically the size of the discrete passive components. The authors introduce multiple power converter circuits, which are very compact as result of their high level of integration. First, the limits of high-power-density low-voltage monolithic switched-capacitor DC-DC conversion are investigated to enable on-chip power granularization. AC-DC conversion from the mains to a low voltage DC is discussed, enabling an efficient and compact, lower-power auxiliary power supply to take over the power delivery during the standby mode of mains-connected appliances, allowing the main power converter of these devices to be shut down fully.

Design and Implementation of Fully-Integrated Inductive DC-DC Converters in Standard CMOS

Design and Implementation of Fully-Integrated Inductive DC-DC Converters in Standard CMOS PDF Author: Mike Wens
Publisher: Springer Science & Business Media
ISBN: 940071436X
Category : Technology & Engineering
Languages : en
Pages : 316

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Book Description
CMOS DC-DC Converters aims to provide a comprehensive dissertation on the matter of monolithic inductive Direct-Current to Direct-Current (DC-DC) converters. For this purpose seven chapters are defined which will allow the designer to gain specific knowledge on the design and implementation of monolithic inductive DC-DC converters, starting from the very basics.