應用於臨界可調式電壓之DC-DC轉換切換式電容晶片

Abstract

本篇論文提出一個操作在0.5伏特的直流對直流轉換器，此電路包含四大部分:比較器、控制數位電路、切換式電容電路以及驗證用的數位電路。參考電壓與輸出回授電壓經由比較器產生的輸出信號交由控制數位電路來控制切換式電容如何動作來達到目標電壓。此轉換器皆為數位控制設計，無靜態功率消耗，並由兩個交錯的相位配置三種架構。電路操作在0.5伏特，輸出可調電壓範圍0.25伏特到0.45伏特之間，負載電流可承受10 µA到100 µA，轉換效能範圍為59-79 %。在負載為0.45伏特以及100µA時，切換式電容消耗57µW，其中待測電路消耗45 µW，效能達到79 %。在最低負載功率下，比較器以及數位電路只消耗2 µW。此晶片使用TSMC GUTM 90 nm CMOS製程實現一高效能轉換之直流對直流轉換降壓切換式電容架構，可應用於植入式生醫晶片的極低功率消耗電路。晶片佈局面積為1mm × 1mm。

This thesis proposes a DC-DC converter operation at 0.5 V. The circuit consists of four parts: a comparator, a digital control circuit, a switched capacitor and a digital circuit under test (DUT). The digital control circuit take the comparator output to control the switched capacitor operation to achieve the target voltage according to the reference voltage. It’s 2-phase interleaved converter can be configured into three topologies, which supports the output voltages of 0.25-0.45 V from the 0.5 V input supply, it has an efficiency between 59-79% for the load current of 100 µA. This converter is designed with all digital control without any static power consumption. At the load of 0.45 V and 100 µA, the switched capacitor consumes 57 µW. Among them, 45 µW is for the DUT with an efficiency of 79 %. The comparator and the digital control consume only 2 µW under lowest load power. It can be applied to implantable biomedical chip with low power consumption circuits. This chip is fabricated in TSMC GUTM 90 nm CMOS process, with high efficiency. The chip area is 1mm × 1mm.