本論文針對數位漣波控制降壓型轉換器進行研究並實現能達到負載快速暫態響應的適應性導通時間控制降壓型轉換器。數位適應性導通時間控制實現採用數位電感電流斜率感測器，可以達到快速暫態響應，同時能使系統穩定且不需要高花費的輸出電壓取樣類比數位轉換器。系統在連續導通模式下，利用參考電壓以及輸入電壓選擇不同的導通時間，使得系統可以操作在準定頻。此系統在極輕載時可以操作在不連續導通模式，以提高極輕載之轉換效率。
本系統之數位控制器應用於可攜式產品規格，實作於FPGA開發版。量測結果顯示降壓型轉換器可以操作在輸入電壓2.7伏特至4.2伏特，輸出電壓範圍可以從0.8伏特至1.2伏特。實驗結果顯示負載暫態從500毫安培至100毫安培回復時間為45微秒，100毫安培至500毫安培回復時間為55微秒。切換頻率變動範圍在連續導通模式下是500千赫至600千赫。最高的效率點在負載為50毫安培下能達到百分之九十五的轉換效率。

This thesis focuses on the study and implementation of digital ripple-based controlled buck converter to realize a buck converter with digital adaptive on-time (AOT) control that achieves a fast load transient response. By using a digital inductor current ramp estimator, the AOT control can not only allow the switching regulator to achieve a fast transient response, but also operate stably without a high cost output voltage sampling analog-to-digital converter (ADC). The digital AOT controller which adjusts the on-time according to the supply voltage and different reference voltage conditions can achieve pseudo-fixed switching frequency in the continuous conduction mode (CCM). And the conversion efficiency under ultralight-load conditions can be improved by working in the discontinuous conduction mode (DCM).
The experimental parameter of the proposed regulator is based on the portable-device application and verified by using a FPGA-based hardware platform. The measurement results show that the buck converter can operate under load current between 10 mA and 500 mA for the supply voltage from 2.7V to 4.2 V and the output voltage range from 0.8 V to 1.2 V. The Experimental result shows the load-transient response time is 45 μs when the load current decreased from 500 mA to 100 mA and 55 μs when the load current increased from 100 mA to 500 mA. The switching frequency range of variation is from 500 kHz to 600kHz at CCM. The peak efficiency is 95 % at 50 mA of the load current.

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