电源备份开关

摘要：一个微处理器监控IC和两个外部MOSFET开关形成一个低电压的备用电源，当主电源发生故障时，可以提供几安培。

Maxim/Dallas>AppNotes>CIRCUITPROTECTIONMICROPROCESSORSUPERVISORCIRCUITSKeywords:backuppowersupplies,microprocessorsupervisors,lowvoltage,MOSFETswitchesAug27,2004APPLICATIONNOTE3323Power-BackupSwitchAmicroprocessor-supervisorICandtwoexternalMOSFETswitchesformalow-voltagebackuppowersupplythatcanprovideseveralampereswhenthemainsupplyfails.Everysubsysteminanelectronicproductdependsonareliablepowersupply.Onewaytoachievehighreliabilityistohaveabackuppowersupply,incasethemainsupplyfails.Theclassicmethodforaddingbackuppoweristohaveeachsupplyconnectedwithaseriesdiodetoacommonoutput.Butwithtoday'slowersupplyvoltages,thepowerlostintheseriesdiode'sforwardvoltagedr