4、將下面的內容翻譯成中文。???????? This?is the battery backup input that powers the SRAM and RTC when main power is removed. Typical? current draw is 15uA. Without an external backup battery, the module/engine board will execute a cold star? after every turn on. To achieve the faster start-up offered by a hot or warm start, a battery backup must be? connected. The battery voltage should be between 2.0v and 5.0v.? ? ?參考翻譯:???????? 這是一個在主電源被移走時給SRAM及RTC供電的電池備份輸入,典型的耗電流為15uA。當沒有這個外部備用電源時,模塊/引?擎板在每次開機的時候都執行冷啟動。為了提高啟動時間,啟動時馬上進入溫啟動或熱啟動,這個備用電池是必須連接的。備 用電池的電壓應為2.0V到5.0V。 ? ? ? ? ?