新型精準自適應定導通時間控制之降壓型轉換器建模與分析

Modeling and Analysis of A Novel Accurate Adaptive Constant On-time Controlled Buck Converters

劉文欽(LIU WEN-CHIN)

指導教授 ： 陳景然

國立臺灣大學/電機資訊學院/電機工程學研究所/碩士(2019年)

https://doi.org/10.6342/NTU201900196

摘要

近年來，斜率補償之漣波調變定導通時間控制架構由於架構簡單、具快速負載暫態響應、輕載時的高轉換效率以及其可穩定操作在陶瓷電容為輸出電容之優點而被廣泛的應用於各式各樣的電子消費性產品之直流轉換器中。然而在功率管理積體電路的應用下，此種架構在寬範圍操作下有穩定度與過衝負載暫態響應之潛在問題。近期，一種精準自適應定導通時間控制策略被提出以解決上述問題，此種控制架構利用簡易的電路成功地在寬範圍輸入下達到精確的輸出電壓調節，固定品質因素以及優秀的負載暫態響應。
本論文利用描述函數的數學分析對精準自適應定導通時間控制架構推導小信號模型並進行分析，最後所提出之電路以類比晶片實現並利用模擬軟體以及實驗結果驗證理論分析。

關鍵字

降壓型電源轉換器 ； 漣波調變定導通時間控制 ； 描述函數 ； 小信號模型

並列摘要

The ripple-based constant on-time (RBCOT) control scheme with ramp compensation has been widely adopted in buck converters in recent years because of its simplicity, fast transient response, high light-load efficiency, and stable operation with ceramic output capacitor. However, this control scheme has the potential issues of feedback instability and excessive load transient response with wide input/output voltage range conditions in the power management integrated circuit (PMIC) applications. Recently, an accurate adaptive constant on-time control (A2COT) scheme was reported to solve these problems. The control scheme achieves accurate output voltage regulation, and nearly a constant quality factor and good transient response over wide-range operation with simple circuit.
In the thesis, small-signal models of the A2COT control is derived based on the describing function (DF) technique for design optimization. Finally, the simulations and experimental verifications were conducted to verify the proposed concepts

並列關鍵字

Buck converters ； Ripple-based constant on-time control ； Describing function

參考文獻

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