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 control (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
· Block diagram · Behavior at large and small LoopGains · The usefriendly graphical representation of the LoopGain
· Overshoot and Q · Output impedance
· Block diagram · What is Aol, what is Beta · Response in closed loop
· Block diagram · Modulator · Demo circuit and response · Characteristics of open loop
· Block diagram · Modulator · Demo circuit and simulated response · Characteristics of open loop
· Modulator · Demo circuit and response · Characteristics of open loop
· 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)
· Shaping Beta · The laglead network · The double zero network
· Block diagram · Discrete control · S to z transformation · The delay issue · A/D and Modulator resolutions · Design example · Comparing analog to digital control

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:


Fundamentals of PWM Converters


Introduction to CMOS Operational Amplifiers


Control Design of PWM Converters:


Fundumentals of PWM Converters


Computer Aided design of Power Factor Correction Systems


Modern Soft Switched Converter Topologies


Control Design of PWM Converters: The User Friendly Approach 

Switched Capacitors Converters


Essentials of Switch Mode Converters


Power Electronics of Piezoelectric Elements


Digital Control Design of PWM Converters: The TimeDomain Approach
