Ltspice: Design A 99% Efficient Buck Converter

Learn how to maximize the efficiency of a buck converter design.

What you'll learn

You will be able to understand what are the critical steps to design a 99% efficient buck converter.

This course is hands-on! All the examples will be designed in LTspice itself instead of using presentation slides

You will understand how to use real components from actual manufacturers instead of having to rely on ideal component models.

You will master several aspects of the LTspice interface, toolbars and commands.

You will learn how to measure power dissipation and efficiency of components.

You will learn about parasitic capacitances of MOSFETs, diodes and inductors and how they influence the efficiency of a buck converter.

Requirements

You are already able to use LTspice, but would like to understand how to use real component models rather than using ideal components.

You already know what a buck converter is, but struggle or wonder how to increase its efficiency.

I use a lot of keyboard shortcuts, if you learn on how to use them too, you can increase your speed when working with LTspice

Description

This course introduces you to the steps that are required to increase the efficiency of a buck converter.When using real component models in LTspice, you have to consider many factors during your component selection.This course will help you to find out which effects are the main causes for degradation of a buck convers efficiency, following terms will be directly or indirectly covered during this course:Diode:     * Forward Voltage     * Current Capability     * Breakdown Voltage     * Reverse Current      * Junction CapacitanceMOSFET:     * On Resistance     * Gate Capacitance and Gate Charge as well as other capacitances that influence the switching behaviour     * Gate Risetime and Gate Falltime     * Switching Frequency     * Dead Time     * Current Conduction via Body Diode     * Gate Driving Requirements     * Safe Operating Area (SOA)     * Shoot-Through Current (Current that flows when High-Side and Low-Side MOSFET are on at the same time)Capacitor:      * Series Resistance     * Series Inductance     * Parallel ResistanceInductor:     * Series Resistance     * Series Capacitance     * Parallel CapacitanceFollowing topics are not being discussed in this course, but are still important for a real world design:Diode:     * Temperature dependence of Forward Voltage and Current     * Temperature dependence of Reverse Current     * Temperature dependence of Junction Capacitance     * Surge Current capability over TemperatureMOSFET:     * Temperature dependence of all above mentioned topics     * Variation of Dead time of the Gate Driver (Jitter)     * dV/dt rugedness of MOSFET (maximum change rate VDS voltage)     * Maximum allowed Power Dissipation over Temperature     * Current Capability of Body DiodeCapacitor:     * Frequency and Temperature dependence of Capacitance     * Temperature dependent allowable Maximum Power Dissipation     * Ripple Current Capability over Temperature     * Aging Effects due to Temperature and ripple current     * Acoustic noise Emission limits (MLCC piezoelectric effect)Electromagnetic Compatibility:     * Emission Limits     * Immunity RequirementsRegulatory Requirements:     * CE, FCC, …     * Hazardous Area Requirements     * Laws limiting import and export of Hazardous Substances (e.g. RoHS)

Overview

Section 1: Introduction

Lecture 1 Introduction

Section 2: Design of a simple buck converter design

Lecture 2 Creation of the initial schematic

Lecture 3 Replace the ideal components with real components

Lecture 4 Measure the circuits efficiency

Lecture 5 Identify the components that cause the most powerlosses

Section 3: MOSFET freewheeling

Lecture 6 Improve efficiency by using a MOSFET instead of a Diode

Lecture 7 Adjust the dead time of the MOSFET and reach 99% efficiency

Section 4: High Frequency Buck Converter Design

Lecture 8 Design of a High Frequency Buck converter

Lecture 9 Transistor Selection Strategy

Lecture 10 Gate Voltage

Lecture 11 Inductor Selection for high Frequencies

Lecture 12 Safe Operating Area

Section 5: Import MOSFET SPICE Models into LTspice

Lecture 13 Introduction and how to import type 1 data packages

Lecture 14 Type 2 data packages (only lib file available, but no symbol file)

Lecture 15 Type 3 data packages (auto generated symbols dont show pin names)

Lecture 16 Type 4 data packages (encrypted lib file)

Lecture 17 Type 5 data packages (only datasheet and or excel tables available)

Lecture 18 Type 6 data packages (provided files have easy to fix errors)

Lecture 19 Type 7 data packages (no detailed data available)

Section 6: Summary and conclusion

Lecture 20 Summary and conclusion

This course is best for people that are already knowledgeable about LTspice but want to level up their design skills.,This is not a beginners course as many keyboard shortcuts are used which can intimidate beginners.