A 4A 12-to-1 Flying Capacitor Cross-Connected DC-DC Converter with Inserted D>0.5 Control Achieving >2× Transient Inductor Current Slew Rate and 0.73× Theoretical Minimum Output Undershoot of DSD

📋 论文概要

针对12V中间总线到低压点负载的高效转换需求，提出一种飞电容交叉连接的DC-DC转换器，采用插入占空比大于0.5的控制策略，实现了超过2倍的瞬态电感性能提升。该拓扑利用飞电容承受半输入电压应力，使大部分开关仅承受半电压，从而可使用低压器件。

💡 主要创新点

• 提出飞电容交叉连接的新型DC-DC拓扑，实现12:1的高降压比，同时降低开关电压应力。
• 引入插入式D>0.5控制方法，显著改善瞬态响应速度，瞬态电感提升超过2倍。
• 所有功率开关（除MA2外）仅承受VIN/2电压，有利于采用低电压工艺器件，提高效率。

🏷 关键词

📄 原文摘要

University of Lisboa, Lisbon, Portugal 1 2 Automotive and industrial applications require a high-efficiency DC-DC converter to directly convert power from the 12V intermediate bus to a low-voltage point-of-load (PoL). The double step-down (DSD) buck converter [1-4] (shown in Fig. 18.3.1) is suitable for such applications, where a flying capacitor CF sustains a half-input-voltage (VIN/2) stress. Therefore, all the power switches only experience VIN/2 stress except MA2, allowing for exploiting the benefits of low-voltage devices. Two pulse-width modulation (PWM) signals Φ1 and Φ2 with an equal duty cycle D drive the DSD. A PoL supply should have a small output capacitor CO if a fast dynamic voltage scaling (DVS) is needed. However, a small CO in the conventional DSD may cause a large output undershoot VUS during a transient event. This comes from the low inductor current slew rate IL_SR=(VIN/2−2VO)/L, due to the amplitude of the inductor switching nodes VXA1 and VXB1

👥 作者与机构

Tingxu Hu1, Mo Huang1, Yan Lu1, Rui P. Martins1,2

University of Macau, Macau, China