Advanced DC/DC converters

• Main Author: He, Yong
• Other Authors: Chang Joseph
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2024
• Subjects: Engineering
• Online Access: https://hdl.handle.net/10356/176151
• Institution: Nanyang Technological University

DC/DC buck converters are the cornerstones in the applications of renewable energy field and portable electronic devices. However, with the growing needs for more compact, efficient, and multi-functional power converters, this project presents an advanced conversion technique aimed at transitioning a Single Inductor Single Output (SISO) DC/DC buck converter to a more versatile and efficient Single Inductor Multiple Output (SIMO) converter. Unlike many existing SIMO designs which often compromise on efficiency, typically dropping to 80~90% to increase the number of outputs. They also face cross regulation problems due to the operation in Continuous Current Mode (CCM). Thus, this SIMO buck converter promises an improved power efficiency of up to 93% and extremely low cross-regulation at 0.001 mV/mA. By leveraging on an existing SISO design that operates in the Boundary Current Mode (BCM), its capabilities are extended to this dual-output SIMO buck converter. This SIMO converter features new components such as load switches and load switch control to enable the successful conversion to achieve superior efficiency and negligible cross regulation. Furthermore, the hysteresis operation mode of the converter also greatly simplified the circuity with mainly the hysteresis comparators and the current sensing modules: Zero Current Detector and Current Sensor. These building blocks are designed such that it helps to minimise the main power losses in switch-mode converters. The fruit of the design effort was the successful tape-out of the final SIMO converter design, marking a significant milestone in the pursuit of optimizing power conversion technologies.