模拟CMOS集成电路设计课件3.CMOS Device Modeling.ppt

* 研 * gmbs的分母项少个1/2次方。 * gm的DC Voltage没有那个2；书上gmbs的DC Voltage分子上面的1/2去掉。 第*页 Other Parameters of LSM Bottom sidewall approximations 第*页 Other Parameters of LSM Bottom sidewall approximations 第*页 Other Parameters of LSM Overlap capacitance 第*页 Other Parameters of LSM Gate to bulk overlap capacitance Channel capacitance 第*页 Other Parameters of LSM 第*页 Other Parameters of LSM 第*页 Other Parameters of LSM 第*页 Other Parameters of LSM 第*页 Small signal model The linearized small signal model 第*页 Small signal model The bulk-drain/source conductance The channel conductance 第*页 Small Signal Model The small signal model is a linearization of the large signal model about a quiescent or operating point Saturation region The small signal model is the linear dependence of id on vgs, vbs, vds. Written as, The complete schematic model An extremely important assumption 第*页 Small signal model The channel conductance – saturation region 第*页 Small signal model The channel conductance – saturation region 第*页 Small signal model The channel conductance – saturation region 第*页 Application(Exercise) Assume that the gate is connected to the drain DC resistor Small signal load (AC resistance) Useful for biasing – creating current from voltage and vice versa Assume that vbs=0 第*页 Small signal model The channel conductance – non-saturation region Similiarly 第*页 Small signal model The channel conductance – non-saturation region 第*页 MOS NOISE 第*页 MOS NOISE 第*页 MOS NOISE 第*页 MOS NOISE 第*页 第*页 Models for Simulation of MOS Circuits FET Model Generations First Generation Physically based analytical model including all geometry dependence Second Generation Model equations became subject to mathematical conditioning for circuit simulation Use of empirical relationship and parameter extraction Third Generation A return to simpler model structure with reduced number of parameters which are physically based rather than empirical. Uses better methods of mathematical conditioning for simulation includi