Design and Practical Implementation of Digital Auto-tuning and Fast-response Controllers for Low-power Switch-mode Power Supplies

Design and Practical Implementation of Digital Auto-Tuning and Fast-Response Controllers for Low-Power Switch-Mode Power Supplies Zhenyu Zhao Doctor of Philosophy Graduate Department of Electrical and Computer Engineering University of Toronto 2008 In switched-mode power supplies (SMPS), a controller is required for output voltage or current regulation. In low-power SMPS, processing power from a fraction of watt to several hundred watts, digital implementations of the controller, i.e. digital controllers have recently emerged as alternatives to the predominately used analog systems. This is mostly due to the better design portability, power management capability, and the potential for implementing advanced control techniques, which are not easy to realize with analog hardware. However, the existing digital implementations are barely functional replicas of analog designs, having comparable dynamic performance if not poorer. Due to stringent constraints on hardware requirements, the digital systems have not been able to demonstrate some of their most attractive features, such as parameter estimation, controller auto-tuning, and nonlinear time-optimal control for improved transient response. This thesis presents two novel digital controllers and systems. The first is an auto-tuning controller that can be implemented with simple hardware and is suitable for IC integration.

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