應用於生物醫學裝置之電池供電97%輸出電壓精確度且 自消除偏移的28奈米降壓型轉換器

Abstract

本文提出了一種應用於生物醫學裝置之電池供電97%輸出電壓精確度且自消除偏移的28奈米降壓型轉換器。由於公眾更加關注醫療服務與品質，便攜式生物醫學裝置的優點，使得醫療行為變得更加便利。基於不斷提高的平均壽命，方便而及時的醫療服務是迫切需要的，例如：遠程監控醫療服務，有助於醫療從業人員通過監測血壓、體溫、心臟跳動等，藉以觀察任何異常症狀，並給予即時的醫療行為或協助。這類型的醫療服務，高度需要便攜式醫療設備的支持，用於便攜式設備的電池是關鍵的組成部分，有了電池的供電才能在任何地方提供服務，因此，已有很多的研究與開發專注於醫療裝置的電池，但直接提供醫療裝置的供電的電源管理單元（Power management unit）也應仔細設計，畢竟可靠性和安全性對於電源供應系統而言是非常重要的，因為任何失效或故障的都是無法接受的，當此設備是涉及到人的生命的時候。另一方面，IEC60601-1國際標準也規定了供電直流電壓的穩定度。基於上述要求，本文所提出的自消除偏移(Offset)轉換器提供一高準確度和穩定的輸出電壓供電給負載系統，自消除偏移轉換器克服了製程與溫度的飄移，提高輸出電壓準確度達到97％，並且不需要任何額外的校準(Trimming)程序。所提出的技術也克服在一般偏移校準(Offset cancellation)方案中的不連續性，並減少常規運算放大器降低偏移所需增加的大量的晶片面積，蒙地卡羅(Monte Carlo)分析用以驗證偏移的降低。此外，臨床醫師和病人也希望能夠提高便攜式醫療設備的功能，高性能的醫療設備服務需要額外的電源供應，渦輪增壓(Turbo-boost)充電器提供更高的功率輸送，但是德州儀器(Texas Instruments)提出的既有方法限制了應用的範圍，因此，本文提出了渦輪增壓充電器的全新的控制架構：全自動控制(Fully automatic control)，透過此創新控制方式，所有的電池供電之應用皆可採用渦輪增壓充電器，藉以符合所需之額外增加的功率。本文從基本的切換式(Switching-based)充電器到渦輪增壓充電器的模型(Model)皆做了完整推導和分析。

This dissertation presents a battery powered self-cancellation DC-DC buck (SC-Buck) converter with 97% output voltage accuracy for biomedical devices in 28nm CMOS process. As the publics are paying more attention on the healthcare services. Advantages of portable biomedical devices become more and more obvious. Due to increasing average lifespan, the convenience healthcare delivery is urgently needed. A remote monitoring service, for example, helps the healthcare practitioners to observe any unusual symptom by monitoring the blood pressure, body temperature, heart beats, etc. These kinds of healthcare services highly depend on the support of portable medical devices. For portable devices, the battery is the key component to deliver power anywhere. Therefore, the battery of a medical device has been developed with lots of efforts. But power management unit (PMU) of medical devices, which directly delivers supplying voltage to systems, should also be carefully designed. Reliability and safety of power sources are important because any failure or malfunction is not a viable option when it comes to human life. On the other hand, IEC60601-1 standard also specifies the stability of supplying DC voltage. Due to above requirements, the proposed SC-Buck converter provides high accuracy and stable output voltage to the loading system. SC-Buck converter overcomes process, voltage and temperature (PVT) variations and increases output voltage accuracy up to 97% without any trimming procedures. The developed technique also overcomes the discontinuity in conventional offset cancellation scheme and reduces large silicon area occupation, which is required to decrease mismatch in conventional operational amplifiers (OPAMPs). Monte Carlo analysis verifies the reduction of mismatch. Furthermore, increasing the functionality of portable medical devices is also expected by clinicians and patients. High performance services require extra power suppling. Thus, Turbo-boost charger developed by Texas Instruments (TI) provides higher power delivery, but restricts the applications. Therefore, this dissertation also presents a new control topology of Turbo-boost charger named as the fully automatic control (FAC) technique, which can support any loading systems. Modeling from basic switching-based charger to the Turbo-boost charger is completely derived and analyzed.