具陣列式開關調變之全積體化多模切換式電容直流-直流轉換器

Abstract

近年來，為延長電池使用時間，系統單晶片之低電壓、低功率消耗已成為趨勢。一般而言，電源管理單元須將電池產生的電源電壓降壓至適當的直流電壓，並提供數微瓦~數毫瓦的輸出功率給負載電路。在此系統中，電源管理單元需利用直流-直流降壓器實現電壓轉換，而其轉換效率會直接影響整體晶片的能源轉換效率。然而晶片外元件除了會導致成本提升外，也難以整合至多核心晶片上。尤其是在系統單晶片應用上，無法使用任何晶片外元件。因此，全積體化直流-直流降壓器是實現多核心應用以及系統單晶片上不可或缺的技術。 本論文所提出的內容，是使用切換式電容直流-直流降壓器來實現全積體化的需求。並在切換式電容轉換器核心電路中，加入數位線性穩壓器的架構，結合了數位線性穩壓器及切換式電容的特性來達到所需之適當直流電壓。另在系統中利用交錯控制技術來降低輸出電壓漣波振幅，以進一步改善穩壓效果。除此之外，為了達到系統低功耗的目的，本論文內所使用之控制電路均使用數位電路來製作。模擬結果顯示本論文所提出之電路架構最高可提供約86%之電壓轉換效率，並在所需求之輸出電壓範圍內均維持高於60%的電壓轉換效率

Recently, low operating voltage and low power consumption for SoC system have become a solution to extend the lifespan of battery. In this case, power management unit is required to convert the output voltage produced by battery to proper dc voltage, and also provides from several uW up to several mW output power to loading circuits. However, in SoC system, any off-chip element will lead to not only the rising of cost, but also increase the difficulty of fully-integration on a multi-core chip. As a result, off-chip elements are not allowed, especially in SoC application. Therefore, fully-integrated dc-dc converter is an essential technique to be implemented in multi-core application and SoC system. In this thesis, the requirement of fully-integration is fulfilled by using switched-capacitor (SC) dc-dc converter. Besides, the topology of digital linear regulator (DLDO) is combined into the converter core circuit. The proposed SC circuit is able to scale output voltage by the characteristic of DLDO. In order to improve the effect of regulation, interleaving technique is utilized to reduce the output voltage ripple. Moreover, to reduce quiescent current, all the control circuits in this thesis are designed as digital circuits. The simulation results show that the proposed circuit is able to provide 86% peak conversion efficiency and remains more than 60% within the range of desired output voltage