28奈米製程應用於手機無線通訊系統並具有暫態增強與能量回收技術的固定導通時間控制降壓電源轉換器

Abstract

隨著資訊與科技的蓬勃發展，攜帶式產品像是手機、平板電腦逐漸在日常生活中扮演不可以或缺的角色。並且，隨著各種應用軟體的蓬勃發展，像是人機介面的互動、醫療人體資訊監測和多媒體的影音串流訊息等。這些龐大的計算量通常都透過手機的通訊系統(Wi-Fi)來傳送與接收。傳統上，通訊系統晶片的電源供應是透過先透過直流降壓電源模組再串接線性穩壓器。目的是為了在比較穩定的電壓供給通訊晶片，穩定的電壓供應能讓通訊系統在傳收的錯誤率上有比較小的失真。但是，線性穩壓器的電壓效率通常都小於80%。因此，傳統串接的供電的方式會有較大電源轉換效率損耗。論文中所提出的供電方式採用直接供電的方式，直接透過直流降壓轉換器供電一穩定低電壓給通訊系統。論文所提出的直流降壓轉換器的基本架構是採用小漣波輸出控制的電源轉換器，並搭配所提出的暫態增強技術與能量回收技術用以減低通訊系統晶片切換到省電模式時對電源產生的突波。比起傳統的直流降壓轉換器供電，本論文所提出的轉換器可以有-6.4dB的錯誤率提升。並且由於能量回收技術的使用，在暫態過電壓輸出時可以擁有98mW的能量回收能力。整體的電源供應效率最高值可以達到93%。

Low voltage Wi-Fi system needs well-regulated supplying power system even in case large load step change. Well-regulation supplying power system needs suppressed output voltage variation including minimized transient undershoot/overshoot voltage variation, steady state voltage variation, and offset voltage effect. State-of-art techniques directly dissipate redundant energy at the output when load changes from heavy to light. Contrarily, proposed multi-phase suppressing output overshoot voltage (MP-SOOV) technique with the help of bond-wire inductance of 33nH has 81.3% overshoot voltage reduction by energy recycling technique and thus simultaneously gets extra power of 98mW in case of load change from 1.7A to 0.3A. Moreover, proposed transient enhancement (TE) technique reduces output undershoot voltage and asynchronous auto-zero (AAZ) technique minimizes the offset effect of core devices in advanced process. Experimental results show 93% peak efficiency, 6mV output voltage ripple with all ceramic capacitors, and -6.4dB improvement in error vector magnitude are achieved by the proposed directly supplying power system.