8 MHz 電流控制模式直流轉直流降壓電源轉換器之電路實現

Abstract

本論文提出了一種新式的高頻率直流轉直流切換式電源轉換器以減少輸出濾波器的面積。由於使用了高切換頻率，使得輸出濾波器在未來有機會被整合入系統晶片中。因此，如何擁有高切換頻率的直流轉直流切換式電源轉換器成為現今技術上重要的發展。所以，將需要一個小型化的系統晶片整合(SoC)解決方案來有效地減少電源管理模組的面積。而且，因為SoC系統的操作電壓太低不能有好的信噪比，也需要一個高效能的電源轉換器模組來提供一個可調節與穩定的系統電壓。為了能提供高效能電源電壓，電流模式控制技術被利用以得到更好的線調節率和負載調節率。不過，高切換頻率將嚴重地影響當電流感測器的準確和反應時間。在這篇論文中也提出了一種高準確以及快反應的電流感測器。 在這篇論文實現切換頻率為8MHz 的電流模式控制降壓穩壓器。此晶片是以台灣積體電路公司 2P4M 0.35u互補式金氧半製程實現，工作電壓範圍為 2.6伏特 至 3.5伏特，其負載調節度和線調節度分別為0.88uV/mA和 4.67 mV/V。因為頻率的提升可以使用較小的外部濾波元件並且可以得到較快的響應因此可加適合用在可攜式元件。

This thesis proposes a new DC-DC switching converter with a high switching frequency for reducing the size of the output filter. Owing to the high switching frequency, the on-chip output filter in DC-DC switching converter is possible in the future. Thus, how to develop a DC-DC switching converter with high switching frequency is important in today’s technology. Therefore, a compact solution is needed to effectively reduce the footprint area of the power management module in system-on-chip (SoC) systems. Furthermore, a high performance power converter module is also needed to provide a regulated and stable supply voltage to the SoC systems because the operation voltage of the SoC systems is too low to have a good signal-to-noise ratio. For providing a high performance supply voltage, the current-mode technique is utilized to get better line and load regulations. However, the current sensing accuracy and response time is seriously affected by the high switching frequency. A high accuracy and small response time current sensor is also proposed in this thesis. In thesis, we implement an 8 MHz current-mode buck DC-DC converter with good line and load regulations. The chip is implemented by tsmc 2P4M 0.35u CMOS process. The range of the operation voltage is from 2.6V to 3.3V. The load regulation and line regulation are 0.88uV/mA and 4.67mV/V. The chip features smaller output filter elements and fast response, which makes it suitable for power management in the portable devices.