Design and Implementation of Switching Converter with High-Voltage Process

隨著手持式裝置的普及，高效率的電源轉換器意味著更長的使用時間；低漣波的電源供應意味著更穩定的電源供給以及更好的消費者體驗。因此，如何提升電源轉換器的轉換效率並減少漣波電壓是一個迫切且重要的課題。 磁滯式切換轉換器有著結構簡單、暫態響應快速以及無條件穩定的優點，然而它的切換頻率是無法被定義的，這將造成電磁干擾濾波器設計上的困難。在我們的第一顆晶片中將使用鎖相迴路的概念針對此問題提出新架構，並且針對輕載以及重載電流的不同調整切換頻率以達到提高效率的目的。這個架構被實現於TSMC 0.25μm 高壓製程。量測結果顯示電感電流為10mA 時，轉換效率可以改善70%；重載時效率也略有改善。此晶片由TSMC 0.25μm 高壓製程所實現。另外，晶片核心電路所佔的面積為387 k μm2 (包含旁路電容)。 另外，由於石化能源的枯竭，再生能源的使用越來越受重視，能量獵取電路的發展也是日趨蓬勃。而目前太陽能電池轉換效率已被提升至44.7%，並持續向50%邁進；高效率太陽能發電已為成勢在必行的重點發展項目。在第二顆晶片中，我們將針對太陽能設計整個能量獵取系統。由太陽能板供應電源約0.5V 的電壓給電荷泵，再由切換式升壓轉換器將電壓3.3V 左右的電壓轉到10V 以上以供給超電容充電使用。另外，由於太陽能電池的特性曲線(電流-電壓曲線)會隨著工作環境而改變，因此最大功率點追蹤也將成為一個問題。此論文將實現此系統中升壓轉換器的部分，這個電路被實現於TSMC 0.25μm 高壓製程。With the popularization of portable devices, a high efficiency power converter means a longer lifetime; a lower ripple indicates a more stable power supply and better consumer experience. Therefore, it is urgent to enhance the power conversion efficiency and lower the ripple voltage. Hysteretic switching converters have advantages such as simple structure, fast transient response and unconditional stable. However, due to its undefined switching frequency, the EMI filter will be hard to design. In our first chip, we introduce a new architecture by using the concept of phase-locked loop. In addition, the switching frequency in light load and heavy load will be optimized in order to enhance the conversion efficiency. The measurement results show that at a 10 mA inductor current, the conversion efficiency can be improved by 70%; the efficiency in heavy load is also slightly improved. This work is fabricated in TSMC 0.25μm. The core of the chip occupies only 387k μm2 (with by-pass capacitors). Also, the exhaustion of fossil fuel cause the importance of renewable energy, the development of energy harvesting circuits is also flourishing. The conversion efficiency of solar cell has come to 44.7% and keep going toward 50%, a high efficiency solar energy will be imperative. In our second chip, we focus on solar energy harvesting system and design a whole system that can convert energy from solar cell to super capacitor. The output voltage of solar cell is about 0.5V, it is fed to a charge pump circuit that can operate under this kind of low voltage. A boost converter is then connected to the charge pump so that it can convert the 3.3V to over 10 V. In addition, the characteristic curve (I-V curve) of the solar cell varies with different operating conditions. Thus, a maximum power point tracking (MPPT) algorithm is needed to optimize the conversion efficiency of the whole system. In this thesis, the boost converter of the system will be implemented. The chip is also fabricated in TSMC 0.25μm HV process