Professional Educational Seminars

Abstract

 

 

     This seminar covers the basics of feedback loop design for operational amplifiers and PWM converters operating in voltage or current mode including analog and digital feedback. It discusses, in an intuitive way, the basic theory and design methods that can be used to close the loop in amplifiers and switch mode systems. The approach to be discussed does not require any elaborate mathematical analysis, yet it is accurate to the level required in practical systems. The proposed design techniques to be discussed in the seminar are based on simulation models that will be covered and demonstrated by many examples.  The seminar addresses the design of analog feedback (for amplifiers and PWM systems) as well as digital control (for PWM systems). The advantages and limitation of each approach will be delineated in relation to present day technology. The issues to be discussed will be supported by design examples and the resulting responses will be demonstrated by simulation.

 

The seminar is of intermediate level intended for novices and experienced engineers in the area of analog and power electronics.


 

Seminar Outline

 

  1. Basics of feedback theory and graphical representation

       Block diagram

       Behavior at large and small LoopGains

       The use-friendly  graphical representation of the LoopGain

  1. Stability criteria
    • Nyquist
    • Bode plain
    • The  Aol, 1/B plots
  2. Relationship between LoopGain and dynamic response

       Overshoot and Q

       Output impedance

  1. Operational Amplifiers bandwidth and stability issues
    • Voltage Feedback Amplifiers (VFA)
    • Current Feedback Amplifiers (CFA)
  2. Compensation by internal circuitry
  3. Compensation by external circuitry
  4. PWM converters as feedback systems

       Block diagram

       What is Aol, what is Beta

       Response in closed loop

  1. Voltage Mode

       Block diagram

       Modulator

       Demo circuit and response

       Characteristics of open loop

  1. Average Current Mode (ACM) control

       Block diagram

       Modulator

       Demo circuit and simulated response

       Characteristics of open loop

  1. Peak Current Mode (PCM) control

       Modulator

       Demo circuit and response

       Characteristics of open loop

  1. Simulation tools

       Cycle by cycle sinusoidal perturbation injection

       PSPICE and PSIM plus demo

       The switched inductor model

       Small signal (AC) analysis

       The duty cycle generator

       Demos of average model and response (Voltage mode, average current peak current mode)

  1. Analog feedback networks in PWM converters

       Shaping Beta

       The lag-lead network

       The double zero network

  1. Digital feedback in PWM converters

       Block diagram

       Discrete control

       S to z transformation

       The delay issue

       A/D and Modulator resolutions

       Design example

       Comparing analog to digital control

  1. Q&A

 

Control Design of PWM Converters: The User Friendly Approach

Computer Aided Analysis and Design

of Single Phase APFC Stages

 

Feedback Design in Operational Amplifiers and  PWM Converters:

The User Friendly Approach

 

Fundamentals of PWM Converters

 

Introduction to CMOS Operational Amplifiers

 

Control Design of PWM Converters:

 The Intuitive Approach

 

Fundumentals of PWM Converters

 

Computer Aided design of Power Factor Correction Systems

 

Power Electronics of Piezoelectric Elements

Introduction to Power Management for Portables

Dynamics and Stability of Switch Mode Converters

Modern Soft Switched Converter Topologies

 

Control Design of PWM Converters: The User Friendly Approach

Switched Capacitors Converters

 

Essentials of Switch Mode Converters

 

מגברי שרת מודרניים

Power Electronics of Piezoelectric Elements

 

Digital Control Design of PWM Converters: The Time-Domain Approach