以固定工作週期的控制方式運用在升壓型轉換器以達到減輕右半部平面零點效應

Abstract

本論文提出一個以固定工作周期控制(solid-duty-control)為基礎的切換式升壓轉換器，當負載變化時保持一樣的工作周期，它可以改善傳統切換式升壓轉換器受到系統右半平面零點(right-half-plane zero)影響，而無法有快速暫態響應(transient response)的問題。藉由適當的遲滯空間調變(adaptive hysteresis window)來控制轉換器的開關時間以便在負載變化時得到固定的工作周期。除此之外，基於可變暫態提升(variable transient enhancement)控制器來提升暫態響應。 此固定工作周期控制(solid-duty-control)為基礎的控制技術可提供LED被剛系統穩地的輸出。篇論文使用TSMC 0.25um CMOS製程技術來進行模擬和製作。經實驗結果顯示，與傳統的電流控制切換式升壓轉換器比較起來，在負載由輕載(50mA)轉為重載(250mA)時，輸出電壓下降變化與穩壓時間較傳統方式分別提升30 % 和 80 %。

his paper proposes a solid-duty-control (SDC) technique to keep a constant duty value to reduce dip voltage during load transient period. It’ll improve the transient response of DC-DC boost converters, which suffer from low bandwidth due to the existence of right-half-plane (RHP) zero. In order to reduce the RHP effect, two controllers are proposed to enhance transient performance. To get contain duty value during load transient period, using adaptive hysteresis window (AHW) modulator control the on-time and off-time of the converter. Besides, due to variable transient enhancement (VTE) controller, the transient response is achieved. The proposed SDC technique can provide a stable and regulated output for edge-lit LED backlight systems. This converter has been implemented in a 0.25-μm CMOS process. Compared to conventional design without any fast transient technique, experimental results show the undershoot voltage and recovery time are improved about 30 % and 80 % as load current suddenly changes from 50mA to 250mA, respectively.