Fundamentals of Closed Loop Design: Using Compensators in Switched-Mode Power Supplies
应用文章
Switched Mode Power Supplies (SMPS) are widely used due to their high efficiency, power density, and programmability. This application note provides a foundational guide to closed loop design using compensators for SMPS. It begins by discussing the need for regulation in power supplies and introduces the concept of closed loop systems, highlighting critical stability metrics and the Nyquist Stability Criterion. This application note explores three primary compensation techniques: integral (I), proportional-integral (PI), and proportional-integral-derivative (PID). Each technique is explained in detail, with guidance on how to select the appropriate method based on system requirements. The practical implementation of these techniques is demonstrated using Keysight's Advanced Design System (ADS) software, illustrating how compensator blocks can streamline the design process. Through detailed examples, the application note demonstrates the design of a closed loop voltage regulator, focusing on achieving the desired bandwidth and phase margin for stable operation. By the end of this application note, readers will gain a solid understanding of the basics of closed loop design using compensators, enabling them to design stable and efficient SMPS tailored to their specific applications.