具有動態遲滯控制且改善輕載及重載時的效能的遲滯降壓電源轉換器

Abstract

在這篇論文呈現了一個新式的動態視窗調便技術用來調整遲滯視窗範圍，在重載時可以降低輸出漣波而在輕載時可以控制操作頻率高於音頻。使用了這個技術使得這個遲滯降壓轉換器在重載時的驅動能力及效能被改善了。除此之外，提出了一個的AB級的電流感測電路，而且提供了一個快的且有效率的準確度，使的遲滯視窗的調整更為準確迅速。量測結果顯示所呈現的動態遲滯視窗調整降壓器在輸出電流為800mA時,不但能夠減少輸出漣波小於12mV,使得效率提升，在輕載時也可以維持操作頻率大於音頻,以防止系統產生不必要的雜訊。

This paper presents a new adaptive window control (AWC) technique to adjust the hysteresis window to reduce the output ripple at heavy loads and keep the switching frequency higher than the acoustic frequency at light loads. Therefore, the driving capability and the power conversion efficiency of the hysteresis converter are improved at heavy loads. Besides, a new class-AB current sensing circuit is also proposed to provide fast and accurate current sensing signal for achieving fast hysteresis window adjustment. Experimental results show that the proposed AWC technique not only reduces the output ripple smaller than 12mV when load current is 800mA to improve the power conversion efficiency but also keeps the switching frequency higher than acoustic frequency at light loads to avoid undesired noise.