應用於物聯網裝置之低互穩壓和低靜態電流疊接型單電感雙輸出直流-直流降壓轉換器

Abstract

新一代物聯網裝置的電力傳輸系統講求輕薄、高效率、低耗能；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電源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無法縮減。單電感雙輸出直流-直流轉換器因此成為優秀的選項，使用單電感及單一晶片的狀況之下可以同時產生兩組電壓。此外，為了實現單晶片系統以降低成本，多半的晶片採用了低電壓邏輯製程，因此單電感雙輸出直流-直流轉換器在架構上必須採用疊接型態以應付較高的輸入電壓，然而，此方法在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，因表現不佳而不適用。本論文依序針對功率級和控制器作設計。在功率級設計方面，採用了輸出點共享的方式使功率及避免過壓，此外，此偏壓方式可大量回收耦合效應所損耗的能量，並有效的降低互穩壓效應。在控制器設計方面，透過額外的瞬態抽載增強機制提升了整體系統在抽載方面的響應。另外，因應物聯網裝置所提出的超輕載模式可有效的減輕了整體控制器在超輕載的靜態電流消耗。

The power management for new generation of Internet of Everything (IoE) devices claims compactness, high performance and low power consumption. To supply multi-outputs for different applications, conventional two-stage topologies are commonly used, where the first stage steps down input voltage to lower voltage level and second stage is 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. As the result, a single-inductor dual-output (SIDO) DC-DC buck converters with the advantage of compact size, have been commonly implemented. However, to achieve fully system on chip (SoC) integration where only low voltage devices are fabricated in nanometer (nm) process, the stacking topologies need to be implemented in SIDO converters to avoid over-voltage operation. However, the coupling effect caused by stacking structures may seriously degrade the performance of SIDO converter. The proposed stacking SIDO DC-DC converter achieves low cross regulation, high ultra-light load (ULL) efficiency, fast transient response, and low quiescent current by the stacking MOSFET driving (SMD) technique. The stacking SIDO with the SMD technique, without external capacitors, reduces the CR to 4.5mV, improves transient response performance about 2 times than conventional SIDO converter. In ULL, a low quiescent current 5uA with no output voltage ripple can be achieved.