DOCSLIB.ORG

Application Note – Using Power MOSFET Z Th Curves

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Application Note – Using Power MOSFET Z Th Curves The Power MOSFET Application Handbook Design Engineer’s Guide NXP Semiconductors Manchester, United Kingdom 3 The Power MOSFET Application Handbook Design Engineer’s Guide Copyright © NXP Semiconductors www.nxp.com ISBN: 978-0-9934854-0-4 12NC: 9397 750 17686 All rights reserved. No part of this publication may be reproduced or distributed in any form or by any means without the prior written permission of the author. Printed in the United Kingdom 4 Contributors: Andrew Berry Chris Hill Adam Brown Kelly Law Brian Clifton Wayne Lawson Jamie Dyer Koji Nishihata Phil Ellis Jim Parkin Mark Fang Christos Pateropoulos Keith Heppenstall Phil Rutter 5 6 Understanding power MOSFET data sheet parameters 1 Power MOSFET single-shot and repetitive avalanche ruggedness rating 2 Using RC Thermal models 3 LFPAK MOSFET thermal design – part 1 4 LFPAK MOSFET thermal design – part 2 5 Using power MOSFETs in parallel 6 Designing RC snubbers 7 Failure signature of electrical overstress on power MOSFETs 8 Power MOSFET frequently asked questions 9 Abbreviations Index Legal Information 7 8 Table of Contents Chapter 1: Understanding power MOSFET data sheet parameters 1.1 Introduction 18 1.2 Data sheet technical sections 18 1.2.1 Product profile 18 1.2.2 Pinning information 21 1.2.3 Ordering information 21 1.2.4 Limiting values 21 1.2.5 Thermal characteristics 30 1.2.6 Electrical characteristics 31 1.2.7 Package outline 42 1.3 Appendices 43 1.3.1 Safe Operating Area (SOA) curves 43 1.4 References 50 Chapter 2: Power MOSFET single-shot and repetitive avalanche ruggedness rating 2.1 Introduction 52 2.2 Single-shot and repetitive avalanche definitions 52 2.3 Understanding power MOSFET single-shot avalanche events 53 2.3.1 Single-shot UIS operation 53 2.3.2 Single-shot avalanche ruggedness rating 56 2.4 Understanding power MOSFET repetitive avalanche events 57 2.4.1 Repetitive UIS operation 58 2.4.2 Temperature components 59 2.5 Repetitive avalanche ruggedness rating 59 2.6 Conclusion 60 2.7 Examples 61 2.7.1 Single-shot avalanche case 61 2.7.2 Repetitive avalanche case 61 2.8 References 62 9 Chapter 3: Using RC Thermal Models 3.1 Introduction 64 3.2 Thermal impedance 64 3.3 Calculating junction temperature rise 65 3.4 Association between Thermal and Electrical parameters 66 3.5 Foster RC thermal models 67 3.6 Thermal simulation examples 70 3.6.1 Example 1 70 3.6.2 Example 2 73 3.6.3 Example 3 77 3.7 Discussions 79 3.8 Summary 80 3.9 References 80 Chapter 4: LFPAK MOSFET thermal design - part 1 4.1 Introduction 82 4.1.1 The need for thermal analysis 82 4.1.2 MOSFET Rth parameters and their limitations 83 4.1.3 Aim of this chapter 84 4.2 General approach to thermal analysis 85 4.2.1 The use of thermal simulation software 85 4.2.2 Simulation set-up 86 4.2.3 PCB layout and stack-up 86 4.3 A single LFPAK device 88 4.3.1 Analysis 1: A single-layer PCB 88 4.3.2 Analysis 2: 2-layer PCB 94 4.3.3 Analysis 3: A 4-layer PCB part 1 96 4.3.4 Analysis 3: A 4-layer PCB part 2 98 4.3.5 Analysis 4: A 4-layer PCB with thermal vias part 1 99 4.3.6 Analysis 4: A 4-layer PCB with thermal vias part 2 102 4.3.7 Summary: factors affecting the thermal performance of a single device 103 4.4 Two LFPAK devices 103 4.4.1 Analysis 5: A single-layer PCB 105 10 4.4.2 Analysis 6: A 2-layer PCB 106 4.4.3 Analysis 7: A generalized 4-layer PCB 107 4.4.4 Analysis 8: A 4-layer PCB with thermal vias part 1 108 4.4.5 Analysis 8: A 4-layer PCB with thermal vias part 2 112 4.4.6 Summary: factors affecting the thermal performance of two devices 113 4.5 Four LFPAK devices 113 4.5.1 Analysis 9: A single-layer PCB 114 4.5.2 Analysis 10: A 2-layer PCB 115 4.5.3 Analysis 11: A generalized 4-layer PCB 116 4.5.4 Analysis 12: A 4-layer PCB with thermal vias part 1 117 4.5.5 Analysis 12: A 4-layer PCB with thermal vias part 2 119 4.5.6 Summary; factors affecting the thermal performance of four devices 121 4.6 Summary 121 Chapter 5: LFPAK MOSFET thermal design - part 2 5.1 Introduction 124 5.2 The module model 125 5.2.1 PCB characteristics 125 5.2.2 Enclosure characteristics 126 5.2.3 Axes naming convention 128 5.2.4 The ambient environment 128 5.2.5 Potential heat paths 128 5.3 The influence of y-gap on Tj 129 5.3.1 Black plastic enclosure; x- and z-gaps = zero 129 5.3.2 Two more enclosure materials 133 5.3.3 Summary: the influence of y-gap on Tj 135 5.4 Adding x- and z-gaps around the PCB 135 5.4.1 The black plastic enclosure 136 5.4.2 The polished aluminium enclosure 137 5.4.3 The anodized aluminium enclosure 138 5.4.4 The three enclosures side-by-side 139 5.4.5 Summary: adding x- and z-gaps around the PCB 141 5.5 Encapsulating the PCB 141 5.5.1 Partial encapsulation 143 11 5.5.2 Full encapsulation 146 5.5.3 Summary: encapsulating the PCB 149 5.6 Direct cooling through the enclosure 149 5.6.1 Bottom-side cooling of the PCB 149 5.6.2 Bottom-side cooling of the PCB, with encapsulation 152 5.6.3 Top-side cooling of the PCB 155 5.6.4 Top-side cooling of the PCB, with encapsulation 158 5.6.5 Summary: direct cooling through the enclosure 160 5.7 Mounting the enclosure on a bulkhead 160 5.7.1 Vertical orientation of the module 161 5.7.2 Adding the bulkhead 162 5.7.3 Results for the PCB mounted centrally in the module 164 5.7.4 Results for the PCB with bottom-side cooling 165 5.7.5 Results for the PCB with top-side cooling 167 5.7.6 Summary: mounting the enclosure on a bulkhead 168 5.8 Summary 168 Chapter 6: Using power MOSFETs in parallel 6.1 Introduction 172 6.2 Static (DC) operation 173 6.2.1 Worked examples for static operation 174 6.3 MOSFET mounting for good thermal performance and power sharing 178 6.4 Power sharing in dynamic operation [pulse and Pulse Width Modulation (PWM) circuits] 181 6.5 Partially enhanced (linear mode) power sharing 183 6.6 Gate drive considerations 184 6.6.1 Should individual gate drivers be used for each MOSFET in the group? 185 6.7 MOSFET packaging considerations for paralleled groups 185 6.7.1 Bare die (KGD) MOSFETs 185 6.7.2 LFPAK MOSFETs 186 6.8 Inductive energy dissipation in paralleled MOSFETs 186 6.8.1 Avalanching - low side MOSFET group driving a high side inductive load 186 12 6.8.2 Active clamping - high side MOSFET group driving a low side inductive load 187 6.9 Summary 188 Chapter 7: Designing RC snubbers 7.1 Introduction 190 7.2 Test circuit 190 7.3 Determining CLK and LLK 192 7.4 Designing the snubber - theory 194 7.5 Designing the snubber - in practice 196 7.6 Summary 197 7.7 Appendix A; determining CLK from Cadd, fRING0 and fRING1 198 Chapter 8: Failure signature of electrical overstress on power MOSFETs 8.1 Introduction 200 8.1.1 ESD - Machine Model 201 8.1.2 ESD - Human body model 203 8.1.3 Unclamped Inductive Switching (UIS) (Avalanche or Ruggedness) 204 8.1.4 Linear mode operation 206 8.1.5 Over-current 208 8.2 Appendices 211 8.2.1 Machine model EOS of BUK9508-55A 211 8.2.2 Machine model EOS of BUK9Y40-55B 212 8.2.3 Machine model EOS of PSMN7R0-30YL 214 8.2.4 Machine model EOS of PSMN011-30YL 215 8.2.5 Human body model EOS of BUK9508-55A 217 8.2.6 Human body model EOS of BUK9Y40-55B 218 8.2.7 Human body model EOS of PSMN011-30YL 219 8.2.8 Unclamped inductive switching EOS of BUK7L06-34ARC 220 8.2.9 Unclamped Inductive switching EOS of BUK9Y40-55B 222 8.2.10 Unclamped inductive switching EOS of PSMN7R0-30YL 223 8.2.11 Linear mode EOS of BUK7L06-34ARC 224 8.2.12 Linear mode EOS of BUK9Y40-55B 226 8.2.13 Linear mode EOS of PSMN7R0-30YL 228 8.2.14 Over-current EOS of BUK7L06-34ARC 230 13 8.2.15 Over-current EOS of PSMN7R0-30YL 232 8.3 Tables 233 8.4 Figures 234 Chapter 9: Power MOSFET frequently asked questions 9.1 Introduction 238 9.2 Gate 238 9.3 Thermal impedance (Zth) curves 239 9.4 MOSFET body diode 244 9.5 Safe operating area and linear mode operation 246 9.6 Avalanche Ruggedness and Unclamped Inductive Switching (UIS) 250 9.7 Capacitive dV/dt issues 258 9.8 Package and mounting 263 9.9 SPICE models 265 9.10 MOSFET silicon technology 266 9.11 Supply and availability 268 9.12 EMC 268 9.13 Leakage, breakdown and MOSFET characteristics 269 9.14 MOSFET reliability 277 14 Introduction Drawing on over 20 years’ of experience, the Power MOSFET Application Handbook brings together a comprehensive set of learning and reference materials relating to the use of power MOSFETs in real world systems.
Load more

Recommended publications
  • Arithmetic and Logic Unit (ALU)
    Computer Arithmetic: Arithmetic and Logic Unit (ALU) Arithmetic & Logic Unit (ALU) • Part of the computer that actually performs arithmetic and logical operations on data • All of the other elements of the computer system are there mainly to bring data into the ALU for it to process and then to take the results back out • Based on the use of simple digital logic devices that can store binary digits and perform simple Boolean logic operations ALU Inputs and Outputs Integer Representations • In the binary number system arbitrary numbers can be represented with: – The digits zero and one – The minus sign (for negative numbers) – The period, or radix point (for numbers with a fractional component) – For purposes of computer storage and processing we do not have the benefit of special symbols for the minus sign and radix point – Only binary digits (0,1) may be used to represent numbers Integer Representations • There are 4 commonly known (1 not common) integer representations. • All have been used at various times for various reasons. 1. Unsigned 2. Sign Magnitude 3. One’s Complement 4. Two’s Complement 5. Biased (not commonly known) 1. Unsigned • The standard binary encoding already given. • Only positive value. • Range: 0 to ((2 to the power of N bits) – 1) • Example: 4 bits; (2ˆ4)-1 = 16-1 = values 0 to 15 Semester II 2014/2015 8 1. Unsigned (Cont’d.) Semester II 2014/2015 9 2. Sign-Magnitude • All of these alternatives involve treating the There are several alternative most significant (leftmost) bit in the word as conventions used to
    [Show full text]
  • FUNDAMENTALS of COMPUTING (2019-20) COURSE CODE: 5023 502800CH (Grade 7 for ½ High School Credit) 502900CH (Grade 8 for ½ High School Credit)
    EXPLORING COMPUTER SCIENCE NEW NAME: FUNDAMENTALS OF COMPUTING (2019-20) COURSE CODE: 5023 502800CH (grade 7 for ½ high school credit) 502900CH (grade 8 for ½ high school credit) COURSE DESCRIPTION: Fundamentals of Computing is designed to introduce students to the field of computer science through an exploration of engaging and accessible topics. Through creativity and innovation, students will use critical thinking and problem solving skills to implement projects that are relevant to students’ lives. They will create a variety of computing artifacts while collaborating in teams. Students will gain a fundamental understanding of the history and operation of computers, programming, and web design. Students will also be introduced to computing careers and will examine societal and ethical issues of computing. OBJECTIVE: Given the necessary equipment, software, supplies, and facilities, the student will be able to successfully complete the following core standards for courses that grant one unit of credit. RECOMMENDED GRADE LEVELS: 9-12 (Preference 9-10) COURSE CREDIT: 1 unit (120 hours) COMPUTER REQUIREMENTS: One computer per student with Internet access RESOURCES: See attached Resource List A. SAFETY Effective professionals know the academic subject matter, including safety as required for proficiency within their area. They will use this knowledge as needed in their role. The following accountability criteria are considered essential for students in any program of study. 1. Review school safety policies and procedures. 2. Review classroom safety rules and procedures. 3. Review safety procedures for using equipment in the classroom. 4. Identify major causes of work-related accidents in office environments. 5. Demonstrate safety skills in an office/work environment.
    [Show full text]
  • The Central Processing Unit(CPU). the Brain of Any Computer System Is the CPU
    Computer Fundamentals 1'stage Lec. (8 ) College of Computer Technology Dept.Information Networks The central processing unit(CPU). The brain of any computer system is the CPU. It controls the functioning of the other units and process the data. The CPU is sometimes called the processor, or in the personal computer field called “microprocessor”. It is a single integrated circuit that contains all the electronics needed to execute a program. The processor calculates (add, multiplies and so on), performs logical operations (compares numbers and make decisions), and controls the transfer of data among devices. The processor acts as the controller of all actions or services provided by the system. Processor actions are synchronized to its clock input. A clock signal consists of clock cycles. The time to complete a clock cycle is called the clock period. Normally, we use the clock frequency, which is the inverse of the clock period, to specify the clock. The clock frequency is measured in Hertz, which represents one cycle/second. Hertz is abbreviated as Hz. Usually, we use mega Hertz (MHz) and giga Hertz (GHz) as in 1.8 GHz Pentium. The processor can be thought of as executing the following cycle forever: 1. Fetch an instruction from the memory, 2. Decode the instruction (i.e., determine the instruction type), 3. Execute the instruction (i.e., perform the action specified by the instruction). Execution of an instruction involves fetching any required operands, performing the specified operation, and writing the results back. This process is often referred to as the fetch- execute cycle, or simply the execution cycle.
    [Show full text]
  • Failure Precursors for Insulated Gate Bipolar Transistors (Igbts) Nishad Patil1, Diganta Das1, Kai Goebel2 and Michael Pecht1
    Failure Precursors for Insulated Gate Bipolar Transistors (IGBTs) 1 1 2 1 Nishad Patil , Diganta Das , Kai Goebel and Michael Pecht 1Center for Advanced Life Cycle Engineering (CALCE) University of Maryland College Park, MD 20742, USA 2NASA Ames Research Center Moffett Field, CA 94035, USA Abstract Failure precursors indicate changes in a measured variable that can be associated with impending failure. By identifying precursors to failure and by monitoring them, system failures can be predicted and actions can be taken to mitigate their effects. In this study, three potential failure precursor candidates, threshold voltage, transconductance, and collector-emitter ON voltage, are evaluated for insulated gate bipolar transistors (IGBTs). Based on the failure causes determined by the failure modes, mechanisms and effects analysis (FMMEA), IGBTs are aged using electrical-thermal stresses. The three failure precursor candidates of aged IGBTs are compared with new IGBTs under a temperature range of 25-200oC. The trends in the three electrical parameters with changes in temperature are correlated to device degradation. A methodology is presented for validating these precursors for IGBT prognostics using a hybrid approach. Keywords: Failure precursors, IGBTs, prognostics Failure precursors indicate changes in a measured variable structure of an IGBT is similar to that of a vertical that can be associated with impending failure [1]. A diffusion power MOSFET (VDMOS) [3] except for an systematic method for failure precursor selection is additional p+ layer above the collector as seen in Figure 1. through the use of the failure modes, mechanisms, and The main characteristic of the vertical configuration is that effects analysis (FMMEA) [2].
    [Show full text]
  • Occupational Exposure to Heat and Hot Environments
    Criteria for a Recommended Standard Occupational Exposure to Heat and Hot Environments DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention National Institute for Occupational Safety and Health Cover photo by Thinkstock© Criteria for a Recommended Standard Occupational Exposure to Heat and Hot Environments Revised Criteria 2016 Brenda Jacklitsch, MS; W. Jon Williams, PhD; Kristin Musolin, DO, MS; Aitor Coca, PhD; Jung-Hyun Kim, PhD; Nina Turner, PhD DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention National Institute for Occupational Safety and Health This document is in the public domain and may be freely copied or reprinted. Disclaimer Mention of any company or product does not constitute endorsement by the National Institute for Occupational Safety and Health (NIOSH). In addition, citations of websites external to NIOSH do not constitute NIOSH endorsement of the sponsoring organizations or their programs or products. Furthermore, NIOSH is not responsible for the content of these websites. Ordering Information This document is in the public domain and may be freely copied or reprinted. To receive NIOSH documents or other information about occupational safety and health topics, contact NIOSH at Telephone: 1-800-CDC-INFO (1-800-232-4636) TTY: 1-888-232-6348 E-mail: [email protected] or visit the NIOSH website at www.cdc.gov/niosh. For a monthly update on news at NIOSH, subscribe to NIOSH eNews by visiting www.cdc.gov/ niosh/eNews. Suggested Citation NIOSH [2016]. NIOSH criteria for a recommended standard: occupational exposure to heat and hot environments. By Jacklitsch B, Williams WJ, Musolin K, Coca A, Kim J-H, Turner N.
    [Show full text]
  • MOSFET - Wikipedia, the Free Encyclopedia
    MOSFET - Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/MOSFET MOSFET From Wikipedia, the free encyclopedia The metal-oxide-semiconductor field-effect transistor (MOSFET, MOS-FET, or MOS FET), is by far the most common field-effect transistor in both digital and analog circuits. The MOSFET is composed of a channel of n-type or p-type semiconductor material (see article on semiconductor devices), and is accordingly called an NMOSFET or a PMOSFET (also commonly nMOSFET, pMOSFET, NMOS FET, PMOS FET, nMOS FET, pMOS FET). The 'metal' in the name (for transistors upto the 65 nanometer technology node) is an anachronism from early chips in which the gates were metal; They use polysilicon gates. IGFET is a related, more general term meaning insulated-gate field-effect transistor, and is almost synonymous with "MOSFET", though it can refer to FETs with a gate insulator that is not oxide. Some prefer to use "IGFET" when referring to devices with polysilicon gates, but most still call them MOSFETs. With the new generation of high-k technology that Intel and IBM have announced [1] (http://www.intel.com/technology/silicon/45nm_technology.htm) , metal gates in conjunction with the a high-k dielectric material replacing the silicon dioxide are making a comeback replacing the polysilicon. Usually the semiconductor of choice is silicon, but some chip manufacturers, most notably IBM, have begun to use a mixture of silicon and germanium (SiGe) in MOSFET channels. Unfortunately, many semiconductors with better electrical properties than silicon, such as gallium arsenide, do not form good gate oxides and thus are not suitable for MOSFETs.
    [Show full text]
  • Computer Monitor and Television Recycling
    Computer Monitor and Television Recycling What is the problem? Televisions and computer monitors can no longer be discarded in the normal household containers or commercial dumpsters, effective April 10, 2001. Televisions and computer monitors may contain picture tubes called cathode ray tubes (CRT’s). CRT’s can contain lead, cadmium and/or mercury. When disposed of in a landfill, these metals contaminate soil and groundwater. Some larger television sets may contain as much as 15 pounds of lead. A typical 15‐inch CRT computer monitor contains 1.5 pounds of lead. The State Department of Toxic Substances Control has determined that televisions and computer monitors can no longer be disposed with typical household trash, or recycled with typical household recyclables. They are considered universal waste that needs to be disposed of through alternate ways. CRTs should be stored in a safe manner that prevents the CRT from being broken and the subsequent release of hazardous waste into the environment. Locations that will accept televisions, computers, and other electronic waste (e‐waste): If the product still works, trying to find someone that can still use it (donating) is the best option before properly disposing of an electronic product. Non‐profit organizations, foster homes, schools, and places like St. Vincent de Paul may be possible examples of places that will accept usable products. Or view the E‐waste Recycling List at http://www.mercedrecycles.com/pdf's/EwasteRecycling.pdf Where can businesses take computer monitors, televisions, and other electronics? Businesses located within Merced County must register as a Conditionally Exempt Small Quantity Generator (CESQG) prior to the delivery of monitors and televisions to the Highway 59 Landfill.
    [Show full text]
  • Console Games in the Age of Convergence
    Console Games in the Age of Convergence Mark Finn Swinburne University of Technology John Street, Melbourne, Victoria, 3122 Australia +61 3 9214 5254 mfi [email protected] Abstract In this paper, I discuss the development of the games console as a converged form, focusing on the industrial and technical dimensions of convergence. Starting with the decline of hybrid devices like the Commodore 64, the paper traces the way in which notions of convergence and divergence have infl uenced the console gaming market. Special attention is given to the convergence strategies employed by key players such as Sega, Nintendo, Sony and Microsoft, and the success or failure of these strategies is evaluated. Keywords Convergence, Games histories, Nintendo, Sega, Sony, Microsoft INTRODUCTION Although largely ignored by the academic community for most of their existence, recent years have seen video games attain at least some degree of legitimacy as an object of scholarly inquiry. Much of this work has focused on what could be called the textual dimension of the game form, with works such as Finn [17], Ryan [42], and Juul [23] investigating aspects such as narrative and character construction in game texts. Another large body of work focuses on the cultural dimension of games, with issues such as gender representation and the always-controversial theme of violence being of central importance here. Examples of this approach include Jenkins [22], Cassell and Jenkins [10] and Schleiner [43]. 45 Proceedings of Computer Games and Digital Cultures Conference, ed. Frans Mäyrä. Tampere: Tampere University Press, 2002. Copyright: authors and Tampere University Press. Little attention, however, has been given to the industrial dimension of the games phenomenon.
    [Show full text]
  • AN5252 Low-Voltage Power MOSFET Switching Behavior And
    AN5252 Application note Low-voltage Power MOSFET switching behavior and performance evaluation in motor control application topologies Introduction During the last years, some applications based on electrical power conversion are gaining more and more space in the civil and industrial fields. The constant development of microprocessors and the improvement of modulation techniques, which are useful for the control of power devices, have led to a more accurate control of the converted power as well as of the power dissipation, thus increasing the efficiency of the motor control applications. Nowdays, frequency modulation techniques are used to control the torque and the speed of brushless motors in several high- and low-voltage applications and in different circuit topologies using power switches in different technologies such as MOSFETs and IGBTs. Therefore, the devices have to guarantee the best electrical efficiency and the least possible impact in terms of emissions. The aim of this application note is to provide a description of the most important parameters which are useful for choosing a low- voltage Power MOSFET device for a motor control application. Three different motor control applications and topology cases are deeply analyzed to offer to motor drive designers the guidelines required for an efficient and reliable design when using the MOSFET technology in hard-switch applications: • BLDC motor in a 3-phase inverter topology • DC motor in H-bridge configuration • DC motor in single-switch configuration AN5252 - Rev 1 - November 2018 - By C. Mistretta and F. Scrimizzi www.st.com For further information contact your local STMicroelectronics sales office. AN5252 Control techniques and brushless DC (BLDC) motors 1 Control techniques and brushless DC (BLDC) motors During the last years, servomotors have evolved from mostly brush to brushless type.
    [Show full text]
  • Design, Implementation, Modeling, and Optimization of Next Generation Low-Voltage Power Mosfets
    Design, Implementation, Modeling, and Optimization of Next Generation Low-Voltage Power MOSFETs by Abraham Yoo A thesis submitted in conformity with the requirements for the degree of Doctor of Philosophy Department of Materials Science and Engineering University of Toronto © Copyright by Abraham Yoo 2010 Design, Implementation, Modeling, and Optimization of Next Generation Low-Voltage Power MOSFETs Abraham Yoo Doctor of Philosophy Department of Materials Science and Engineering University of Toronto 2010 Abstract In this thesis, next generation low-voltage integrated power semiconductor devices are proposed and analyzed in terms of device structure and layout optimization techniques. Both approaches strive to minimize the power consumption of the output stage in DC-DC converters. In the first part of this thesis, we present a low-voltage CMOS power transistor layout technique, implemented in a 0.25µm, 5 metal layer standard CMOS process. The hybrid waffle (HW) layout was designed to provide an effective trade-off between the width of diagonal source/drain metal and the active device area, allowing more effective optimization between switching and conduction losses. In comparison with conventional layout schemes, the HW layout exhibited a 30% reduction in overall on-resistance with 3.6 times smaller total gate charge for CMOS devices with a current rating of 1A. Integrated DC-DC buck converters using HW output stages were found to have higher efficiencies at switching frequencies beyond multi-MHz. ii In the second part of the thesis, we present a CMOS-compatible lateral superjunction FINFET (SJ-FINFET) on a SOI platform. One drawback associated with low-voltage SJ devices is that the on-resistance is not only strongly dependent on the drift doping concentration but also on the channel resistance as well.
    [Show full text]
  • What Is a Microprocessor?
    Behavior Research Methods & Instrumentation 1978, Vol. 10 (2),238-240 SESSION VII MICROPROCESSORS IN PSYCHOLOGY: A SYMPOSIUM MISRA PAVEL, New York University, Presider What is a microprocessor? MISRA PAVEL New York University, New York, New York 10003 A general introduction to microcomputer terminology and concepts is provided. The purpose of this introduction is to provide an overview of this session and to introduce the termi­ MICROPROCESSOR SYSTEM nology and some of the concepts that will be discussed in greater detail by the rest of the session papers. PERIPNERILS EIPERI MENT II A block diagram of a typical small computer system USS PRINIER KErBOARD INIERfICE is shown in Figure 1. Four distinct blocks can be STDRIGE distinguished: (1) the central processing unit (CPU); (2) external memory; (3) peripherals-mass storage, CONTROL standard input/output, and man-machine interface; 0111 BUS (4) special purpose (experimental) interface. IODiISS The different functional units in the system shown here are connected, more or less in parallel, by a number CENTKll ElIEBUL of lines commonly referred to as a bus. The bus mediates PROCESSING ME MOil transfer of information among the units by carrying UN IT address information, data, and control signals. For example, when the CPU transfers data to memory, it activates appropriate control lines, asserts the desired Figure 1. Block diagram of a smaIl computer system. destination memory address, and then outputs data on the bus. Traditionally, the entire system was built from a CU multitude of relatively simple components mounted on interconnected printed circuit cards. With the advances of integrated circuit technology, large amounts of circuitry were squeezed into a single chip.
    [Show full text]
  • Fundamentals of MOSFET and IGBT Gate Driver Circuits
    Application Report SLUA618A–March 2017–Revised October 2018 Fundamentals of MOSFET and IGBT Gate Driver Circuits Laszlo Balogh ABSTRACT The main purpose of this application report is to demonstrate a systematic approach to design high performance gate drive circuits for high speed switching applications. It is an informative collection of topics offering a “one-stop-shopping” to solve the most common design challenges. Therefore, it should be of interest to power electronics engineers at all levels of experience. The most popular circuit solutions and their performance are analyzed, including the effect of parasitic components, transient and extreme operating conditions. The discussion builds from simple to more complex problems starting with an overview of MOSFET technology and switching operation. Design procedure for ground referenced and high side gate drive circuits, AC coupled and transformer isolated solutions are described in great details. A special section deals with the gate drive requirements of the MOSFETs in synchronous rectifier applications. For more information, see the Overview for MOSFET and IGBT Gate Drivers product page. Several, step-by-step numerical design examples complement the application report. This document is also available in Chinese: MOSFET 和 IGBT 栅极驱动器电路的基本原理 Contents 1 Introduction ................................................................................................................... 2 2 MOSFET Technology ......................................................................................................
    [Show full text]