用於醫療設備供電的高效熱電獵能升壓直流轉換器

Abstract

近年來，許多醫療相關的物聯網裝置產品逐漸的出現在人們身邊，但是對於許多小型低功耗的貼身感測的醫療監測產品而言，在大型場域中要更換電池不是一件容易的事，因此，透過獵能元件來擷取周圍環境中的可再生能源來為儀器供電成為了一個很好具可行性的解決方案，但這些元件往往需要一個升壓電路來給IoT 供電。因此，本研究提出了一種具有寬輸入電壓範圍的升壓直流-直流轉換器。考慮到應用場景多為輕載，採用了脈衝忽略調變（Pulse Skipping Modulation,PSM）方法來降低切換損耗，並透過具數位調整失調電壓的比較器來最大限度地減少反向電流耗損，以提升系統在輕載下的效率。這款轉換器晶片使用台灣積體電路公司（TSMC）提供的180nm 1P6M 混合信號標準CMOS 製程實現，晶片面積為1197μm × 1192μm，輸入電壓範圍從50mV-400mV，提供的輸出電壓為1.2V。由後模擬結果顯示峰值效率為90.4%，實際量測效率則為86.4%。

In recent years, various medical-related IoT devices have emerged around us. However, for many small, low-power wearable medical monitoring products, replacing batteries over a large area can be challenging.Therefore, utilizing energy harvesting components to capture renewable energy from the surrounding environment has become a feasible solution for powering such devices. These components often require a boost converter to supply power to the IoT devices. This study proposes a boost DC-DC converter with a wide input voltage range. Considering that the application scenario often involves light loads, adopted Pulse Skipping Modulation (PSM) to reduce switching losses and employed a comparator with digitally adjustable offset voltage to minimize reverse current losses, thereby enhancing efficiency under light loads. The converter chip is implemented using TSMC 180nm 1P6M mixedsignal standard CMOS process, with a chip area of 1197μm × 1192μm. It supports an input voltage range from 50mV to 400mV and provides an output voltage of 1.2V. Post-simulation results indicate a peak efficiency of 90.4%, while measured efficiency reaches 86.4%.