实现基于温度 NLX电源供应器的风扇速度控制

TheNLXPowerSupplySpecificationreleasedbyIntel

®

Corporationdefinestherequirementsfornext-genera-

tionPCsystempowersupplies.Thereareseveral

enhancementsoutlinedinthisspecificationascom-

paredtothe“old”PS/2powersupplyformfactor.Oneof

thesefeaturesiscontrolandmonitoringofthecooling

fan(s)insidetheNLXpowersupply.TheNLXspecifica-

tiondesignatestwointerfacefancontrolsignals:

1.FanMsignalisanoutputfromtheNLX-compli-

antpowersupply.Thissignalallowsthehost

(typicallyasystemmanagementASIC)tomoni-

torfanRPM.FanMisanopen-collectorsignal

consistingoftwopulsesperfanrotation.

2.FanCisaninputtotheNLX-compliantpower

supplyusedbythemotherboardtoregulatefan

speedandtoshutthefandown.FanCisa0Vto

12Vanalogsignal.MAN764ImplementingTemperature-BasedVariableFanSpeedControlinNLXPowerSupplies1.LinearVoltageControl:ThismethodvariestheAuthor:MicrochipTechnologyInc.DCvoltageattheVDDterminalofthefaninalin-earmanner.Forexample,a+12VnominalfanINTRODUCTIONmodulatedlinearlyto+8Vwouldtheoreticallyrunat66.7%RPM.Thoughthisseemsrel