Analyses of Single-Inductor Dual-Output (SIDO) DC/DC Converters

單一電感雙組輸出之直流/直流轉換器在近幾年來被應用在手持式電池供電的電子產品上。其電路的操作情形與電路的基本關係，例如電壓增益、開關導通比例、與負載電流的關係，相較與單組輸出的轉換器來得複雜許多。在本論文中，針對三種基本的單一電感雙組輸出之轉換器，包括降壓型、昇壓型與雙極性之轉換器，提出全面性的分析並建立其直流特性方程式。從分析的結果，一種新操作模式的發現，稱作“混壓轉換”模式將被提出。之所以會稱作“混壓轉換”模式，有別於傳統的想法，發現單一電感雙組輸出之降壓型轉換器與單一電感雙組輸出之昇壓型轉換器，分別都可以被拿來提供一組降壓和一組昇壓的輸出。至於單一電感雙組輸出之雙極性轉換器在此模式下，也能提供一組降壓的正極輸出，在之前被認為不可能。因此，這可能性不僅可以帶來一些新的應用，另外針對目前的應用也能延長電池電壓的操作範圍。模擬與實驗的結果被提出，拿來驗證理論的分析。A single-inductor dual-output (SIDO) DC/DC converter has recently found applications in hand-held battery-powered electronic devices. The circuit operation and the functional interdependencies among basic converter parameters such as DC voltage gains, transistor duty cycles, and load current levels are much more complicated than those of the single-output counterpart. In this dissertation, a comprehensive analysis is conducted to develop DC characteristic equations for three basic SIDO converters: SIDO buck, SIDO boost, and SIDO bipolar converters. From the analysis results, a discovery of a new mode of operation, dubbed “mixed-voltage” operation, is pointed out. In the so-called “mixed-voltage” operation, it was discovered, contrary to conventional thinking, that the SIDO buck and SIDO boost can respectively step-up and step-down one of the output voltages. And the SIDO bipolar can also step down the positive output voltage previously deemed not possible. Therefore, this possibility not only opens up new applications but also may extend the workable battery range in existing applications. Simulation and experimental results are presented to confirm the theoretical results