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1、u Structure:complement switchsu steady state:voltage and current u Dynamic state:Speed and costChapter 3 Digital circuitBasic structure:Switch modelAny node in circuit must get 1/0 from Vcc/Gnd by switchesSwitch is made by MOS device Switch model for MOS transistor Switch is controlled by G through
2、electric field;Off:RD-S is high;On:RD-S is low;PMOS:when G is 0,Switch on;when G is 1,Switch off;NMOS:when G is 1,Switch on;when G is 0,Switch off;Two types of MOS transistorCMOS inverter F:get 1 from PMOS,get 0 from NMOS;When X=1,NMOS is on;When X=0,PMOS is on;Why must be complement?NAND /NORNAND:N
3、MOS serial,PMOS parallel;NOR:NMOS parallel,PMOS serial;Each input control a PMOS and an NMOS;AND-series OR-parallelLogic is represented by NMOS connections,PMOS is a duality connection.NAND /NOR AOI /OAI Basic structuer of CMOSEach input is connected both NMOS and PMOS;The logic is expressed in N ne
4、t,P net is its duality;The output is a negative logic!Output of the positive logic Buffer AND gate Add an inverter to the inverse output!CMOS transmission gate(TG)Three state output:0/1/ZWhen c=1,signal is passedWhen c=0,signal is cutoff Three state buffer Three state inverter Circuit made by tri-state devices XOR gate MUX 2Open gate and wired logic Only N-net exist,Output:0/Z;Get 1 by pull-up resistor;The outputs can be connected to get AND logic.