具有過流和過壓關(guān)斷功能的汽車類電池反向保護參考設(shè)計

　　PMP9498是一套完整的前端保護解決方案，適用于需要反向電壓、過壓或過流保護的汽車系統(tǒng)。它還實現(xiàn)了負載開關(guān)功能，能夠以數(shù)字方式控制負載與輸入電源的連接和斷開。該設(shè)計可滿足汽車應(yīng)用在關(guān)閉期間的低智商要求，并且采用了強大的柵極電流源（典型值30 ma），可驅(qū)動大功率MOSFET，因此適合高電流應(yīng)用。

　　The LM74160 smart diode solution is a floating solution with a charge pump to drive an external Nchannel MOSFET. The advantage of this is zero-Iq operation since there is no ground pin. In order to operate and charge the charge pump capacitor （C6）， the MOSFET （Q1） must conduct through its body diode at a 1% duty cycle during forward conduction. Then， the MOSFET gate will be driven for 99% duty cycle， during which the current will flow through its RDS（ON） 。 This operation scheme allows for very efficient， diode-like operation， but without the continuous diode voltage drop.