数字逻辑3-1n

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1、Structure:complementswitchssteadystate:voltageandcurrentDynamicstate:SpeedandcostChapter3DigitalcircuitBasicstructure:SwitchmodelAnynodeincircuitmustget1/0fromVcc/GndbyswitchesSwitchismadebyMOSdeviceSwitchmodelforMOStransistorSwitchiscontrolledbyGthroughelectricfield;Off:RD-Sishigh;On:RD-Si

2、slow;PMOS:whenGis0,Switchon;whenGis1,Switchoff;NMOS:whenGis1,Switchon;whenGis0,Switchoff;TwotypesofMOStransistorCMOSinverterF:get1fromPMOS,get0fromNMOS;WhenX=1,NMOSison;WhenX=0,PMOSison;Whymustbecomplement?NAND/NORNAND:NMOSserial,PMOSparallel;NOR:NMOSparallel,PMOSserial;EachinputcontrolaP

3、MOSandanNMOS;AND--seriesOR--parallelLogicisrepresentedbyNMOSconnections,PMOSisadualityconnection.NAND/NORAOI/OAIBasicstructuerofCMOSEachinputisconnectedbothNMOSandPMOS;ThelogicisexpressedinNnet,Pnetisitsduality;Theoutputisanegativelogic!OutputofthepositivelogicBufferANDgateAddaninvertertothe

4、inverseoutput!CMOStransmissiongate(TG)Threestateoutput:0/1/ZWhenc=1,signalispassedWhenc=0,signaliscutoffThreestatebufferThreestateinverterCircuitmadebytri-statedevicesXORgateMUX2OpengateandwiredlogicOnlyN-netexist,Output:0/Z;Get1bypull-upresistor;TheoutputscanbeconnectedtogetANDlogic.