可兼容 DCM 之 具自適應導通時間控制的 Pi 型雙路混合降壓轉換器

Abstract

本論文提出一種具自適應導通時間控制的 Pi 型雙路混合降壓型轉換器，旨在解決可攜式與穿戴式裝置中，實現高電流密度與寬負載範圍下高效率的挑戰。所提出的 Pi 型雙路混合降壓型轉換器繼承了先前雙路混合降壓型轉換器拓撲在降低電感器電流的優勢，同時解決了與不連續導通模式相關的關鍵問題，如不準確的零電流檢測和飛輪電容器漏電問題。由於飛行電容器可自我平衡，消除了額外控制電路的需求，並確保在三個操作模式中都能穩定運行。具自適應導通時間控制使得在不連續導通模式中實現脈衝頻率調變，在連續導通模式中則保持固定頻率，使得輕負載和重負載條件下均能保持高效率。該轉換器使用台積電 0.18 μm HV CMOS（T18HVG2）製程製作，並在連續導通模式中以 1.1 MHz的切換頻率運行，在不連續導通模式中則具有可變頻率。測量結果表明，該轉換器在 10 mA 至 1.2 A 的廣泛輸出電流範圍內，效率均超過 80%。該轉換器可提供 3.6 V 至 4.2 V 的輸入電壓範圍，0.6 V 至 1.0 V 的輸出電壓範圍，並且能處理高達 1.5 A 的輸出電流，同時使用尺寸為 2.00 mm × 1.25 mm × 1.00 mm 的小型功率電感器。與先前的研究相比，該設計實現了優越的負載電流動態範圍（150 倍）和最高的電流密度，證明其在高性能、空間受限的應用中的適用性。

This thesis proposes a Pi-Type Dual-Path Buck (PTDP-Buck) converter with adaptive on-time (AOT) control, aiming to address the challenge of achieving high current density and high efficiency across a wide load range in portable and wearable devices. The PTDP-Buck converter inherits the low inductor current advantages of previous dual-path buck (DP-Buck) topologies while resolving critical issues associated with discontinuous conduction mode (DCM), such as inaccurate zero current detection (ZCD) and flying capacitor leakage. Due to the self-balancing ability of the flying capacitor, the need for additional control circuitry is eliminated, ensuring stable operation across all three operating modes. AOT control enables pulse frequency modulation (PFM) in DCM and fixed-frequency in continuous conduction mode (CCM), maintaining high efficiency under both light and heavy load conditions. Fabricated using the TSMC 0.18 μm HV CMOS (T18HVG2) process, the converter operates at 1.1 MHz switching frequency in CCM and with a variable frequency in DCM. Measurement results demonstrate an efficiency exceeding 80% across a wide output current range from 10 mA to 1.2 A. The converter supports input voltages from 3.6 V to 4.2 V, output voltages from 0.6 V to 1.0 V, and output currents up to 1.5 A, all while using a small 2.00 mm × 1.25 mm × 1.00 mm power inductor. Compared with prior works, this design achieves a superior load current dynamic range (150×) and the highest current density, confirming its suitability for high-performance, space-constrained applications.