本文提出一個超低耗電流過電壓保護技術及裝置，目的在提供受偵測電壓超過一設定之額定電壓時可輸出一控制信號，可用來重置或保護在受測電壓下使用之元件或迴路系統。過電壓保護電路主要包含參考電壓方塊、參考電流方塊、比較器電路、時脈產生器、數位計數器及電壓調節器等。此電路實現在0.4微米高壓製程上，並操作在兩組操作電壓下。其低壓部分操作電壓為5伏特，高壓部分操作電壓最高可達30伏特，提供可選擇的保護電壓範圍3.5-4.8伏特， 且電流消耗僅為1.4微安培。另外此保護裝置也提供可調範圍為0.5毫秒-10秒的過壓偵測延遲時間及當保護電壓回復正常狀態時2-3毫秒的回復延遲時間。此技術及裝置可應用在低功耗上電重置電路、電池電壓保護、電池充放電迴路系統及LED驅動裝置等應用中。

This paper presents the design of an overvoltage protection technique for ultra-low-current device. It can be used to reset and protect the devices and systems operating under the protected voltage. The device is consisted of a voltage reference, a current reference, comparator circuits, a clock generator, a digital counter, and a voltage regulator. The chip is fabricated in a 0.4um CMOS technology and operated with two supply voltages. One supply voltage is 5V and the other is 30V. The overvoltage protection range is 3.5V to 4.8V, and the current consumption is only 1.4uA. Additionally, the adjust delay time of 0.5ms to 1s for overvoltage detection and a recovered time of 2-3ms are provided. The device can be used at a low-power power-on-reset circuit, a battery protection system, a charger/discharger system, and a LED driver system.