應用於通用串列匯流排電力傳輸之高效率單電感多輸出直流-直流降壓轉換器

Abstract

新一代通用串列匯流排之電力傳輸規格，從原本低瓦數的五伏特，演進到最高一百瓦數二十伏特的傳輸規範；傳統上多以兩級串聯轉換器之方式，將高輸入電壓經由第一級轉換器降壓後，再經由第二級轉換器轉換成多組店員分別供應不同電路區塊，此兩級架構以及多組電源之需求，造成目前市面上的產品多半使用多組直流-直流降壓轉換器以及多個外部電感來實現此電源供應模組，因此在印刷電路板的面積以及成本上遲遲無法縮減。單電感多輸出直流-直流轉換器因此成為優秀的選項，使用一個外部電感及單一晶片的狀況之下可以同時產生多組電壓。然而，根據前述通用串列匯流排電力傳輸規格，較大的輸入電壓以及其範圍，會使得現今文獻所提出的單電感多輸出直流-直流轉換器在效率和控制器實現上，表現不佳而不適用。本論文依序針對控制器和功率級作設計。在控制器設計方面，提出之合成波行之電流控制模式，解決由高輸入電壓及低轉換比率造成之控制實現難度。在功率級設計方面，藉由控制方式降低功率電晶體之導通阻抗，以達到高效率的表現。本論文提出一大輸入範圍高效率應用於通用串列匯流排之單電感多輸出直流-直流轉換器。

New generation of universal serial bus power delivery specification of 100 W (20V at 5A) induces the potential of high power delivery power management system. With the USB Power Delivery (PD) Specification Revision 2.0, details how a USB link can delivery from a 4.5-W power source (900 mA at 5 V) to a 100-W (5 A at 20 V). This induces a potential for quickly charging smartphones and tablets by directly using USB with high power delivery. Conventional two-stage hierarchy is applied to this high input voltage application, where the first stage step down input voltage to lower voltage level and second stage composed of several converters finally provide different voltages according to different function blocks. This power unit requires lots of DC-DC buck converter chips with many inductors form the power solutions and thus consumes large PCB area and cost. A single-inductor multiple-output (SIMO) DC-DC buck converters with the advantage of compact size, have been commonly implemented. This thesis divides the design of SIDO converter into two parts, controller design and power stage design. Controller design with the proposed synthesized waveform controlled frequency (SWCF) technique is proposed to solve the problem which is caused from high input voltage. Power stage design including low on-resistance controlled technique is illustrated. Finally, the SIDO DC-DC converter with high efficiency and wide input voltage is developed in this thesis.