拉扎维模拟CMOS集成电路设计第二章作业答案-中文

Copyrightforzhouqn第二章作业答案Copyrightforzhouqn2.1、W/L=50/0.5，假设|VDS|=3V，当|VGS|从0上升到3V时，画出NFET和PFET的漏电流VGS变化曲线解：a)NMOS管：假设阈值电压VTH=0.7V,不考虑亚阈值导电①当VGS0.7V时，NMOS管工作在截止区，则ID=0②当VGS0.7V时，NMOS管工作在饱和区，NMOS管的有效沟道长度Leff=0.5-2LD，则21()(13)2DnoxGSTHneffWICVVL3212.810(0.7)DGSIV2350//ncmVs60.0810DLm10.1nV20323.83710/siooxoxCFmt9910oxtm1208.85410/Fm23.9sioCopyrightforzhouqna)PMOS管：假设阈值电压VTH=-0.8V,不考虑亚阈值导电①当|VGS|0.8V时，PMOS管工作在截止区，则ID=0②当|VGS|≥0.8V时，PMOS管工作在饱和区，PMOS管的有效沟道长度Leff=0.5-2LD，则21()(13)2DpoxGSTHpeffWICVVL324.810(0.8)DSGIV2100//pcmVs60.0910DLm10.2pV20323.83710/siooxoxCFmt9910oxtm1208.85410/Fm23.9sioCopyrightforzhouqn2.2W/L=50/0.5,|ID|=0.5mA，计算NMOS和PMOS的跨导和输出阻抗，以及本证增益gmro解：本题忽略侧向扩散LD23.66/mnoxDWgCImAVL1）NMOS311200.10.510onDrkI333.6610201073.2mogr2）PMOS21.96/mPoxDWgCImAVL311100.20.510oPDrkI331.9610101019.6mogr20323.83710/siooxoxCFmt41.3422510//noxCFVs2100//pcmVs53.83510//poxCFVsCopyrightforzhouqn•2.3导出用ID和W/L表示的gmro的表达式。画出以L为参数的gmro~ID的曲线。注意λ∝L2moxDWgCIL解：1oDrI12mooxDDDWWLgrCIALIICopyrightforzhouqn2.4分别画出MOS晶体管的ID~VGS曲线。a)以VDS作为参数；b)以VBS为参数，并在特性曲线中标出夹断点212DnoxGSTHWICVVL解：以NMOS为例+-VGS+-VBS+-VDS当VGSVTH时，MOS截止，则ID=0当VTHVGSVDS+VTH时，MOS工作在饱和区当VGSVDS+VTH时，MOS工作在三极管区（线性区）212DnoxGSTHDSDSWICVVVVLIDVGSVTHVDS1+VTHVDS2+VTHVDS3+VTH斜率正比于VDSVTH0VGSIDVTH1VDS+VTH0VDS+VTH1VSB=0VSB0Copyrightforzhouqn2.5对于图2.42的每个电路，画出IX和晶体管跨导关于VX的函数曲线草图，VX从0变化到VDD。在(a)中，假设Vx从0变化到1.5V。（VDD=3V）2112XnoxGSTHDSWICVVVL(a)+-VXVDDM1Ix10.1nV1/20.45V20.9FV00.7THVV3GSDDXXVVVV3DSDDXXVVVVSBXVV022THTHFSBFVVV2130.70.450.90.9132XnoxXXXWICVVVL上式有效的条件为30.70.450.90.90XXVV即1.97XVVCopyrightforzhouqn(a)综合以上分析VX1.97V时，M1工作在截止区，则IX=0,gm=0VX1.97V时，M1工作饱和区，则212.7270.460.9(1.30.1)2XnOXXXXWICVVVL2mnOXXWgCILCopyrightforzhouqn(b)λ=γ=0,VTH=0.7V+-1VM1+-VX1.9VIX①当0VX1V时，MOS管的源-漏交换1.9GSXVV21[(1.2)(1)0.5(1)](1.4)(1)2XnOXXXXnOXXXWWICVVVCVVLL1DSXVV1.2DSATonXVVV工作在线性区，则(1)mnOXDSnOXxWWgCVCVLL②当1VVX1.2V时,MOS管工作在线性区211[20.2(1)(1)](1.4)(1)22XnOXXXnOXXXWWICVVCVVLL(1)mnOXDSnOXxWWgCVCVLLCopyrightforzhouqn+-1VM1+-VX1.9VIX③当VX≥1.2V时,MOS管工作在饱和区2211()(0.2)22XnOXGSTHnOXWWICVVCLL()0.2mnOXGSTHnOXWWgCVVCLLCopyrightforzhouqn(C)λ=γ=0,VTH=0.7V①当VX0.3V时，MOS管的源-漏交换，工作在饱和区1GSXVV1.9DSXVV0.3DSATonXVVV+-1.9VM1+-VX1VIX2211()(1)22XnOXGSTHnOXXWWICVVCVLL()(1)mnOXGSTHnOXXWWgCVVCVLL②当VX≥0.3V时，MOS管工作截止区0XI0mgCopyrightforzhouqn(d)λ=γ=0,VTH=-0.8V①当0VX≤1.8V时，MOS管上端为漏极，下端为源极，MOS管工作在饱和区0.9GSVV1.9DSXVV0.1DSATonVVV+-1.9VM1+-VX1VIX21(0.1)2XPoxWICL(0.1)mPoxWgCL②当1.8VVX≤1.9V时，MOS管工作在线性区21[2(0.1)(1.9)(1.9)]2XPoxXXWICVVL(1.9)mPoxXWgCVLCopyrightforzhouqn+-1.9VM1+-VX1VIX1GSXVV③当VX1.9V时，MOS管S与D交换MOS管工作线性区1.9DSXVV21[2(1)(1.9)(1.9)]2XPoxXXXWICVVVL(1.9)mPoxXWgCVLCopyrightforzhouqn(e)λ=0,当VX=0时,VTH=0.893V，此时MOS工作在饱和区+-1VM1+1.5VVX1.9VIX+-1/20.45V20.9FV00.7THVV0.9GSVV0.5DSV0(22)0.70.45(0.90.9)THTHFSBFSBVVVV1SBXVV21[0.20.45(1.90.9)]2DnOXXWICVL[0.20.45(1.90.9)]mnOXXWgCVL随着VX增加，VSB降低，VTH降低，此时MOS管的过驱动电压增加，MOS管工作在饱和区；直到过驱动VDSAT上升到等于0.5V时，MOS管将进入线性区，则有0.20.45(1.90.90.51?2???.8XXVVVCopyrightforzhouqn+-1VM1+1.5VVX1.9VIX+-当VX1.82V时，MOS管工作在线性区？？？？21{20.5[0.20.45(1.90.9)]0.5}2DnOXXIWCVL2(0.5)mnOXWgCLCopyrightforzhouqn2.7对于图2.44的每个电路，画出Vout关于Vin的函数曲线草图。Vin从0变化到VDD=3V。解：+-1VM1VinVoutR1(a)λ=γ=0,VTH=0.7V右图中，MOS管源-漏极交换•当Vin0.7V时，M1工作在截止区，Vout=0•当0.7Vin≤1.7V时，M1工作在饱和区，则211(0.7)2outDnOXinoutWVICVVRL•当1.7VVin3V时，M1工作在线性区，则21[2()(1)(1)]outDnOXinoutTHoutoutWVICVVVVVRL+-1VM1VoutR1VinCopyrightforzhouqn2.7(b)λ=γ=0,VTH=0.7V+-2VM1VinVoutR1•当0Vin1.3V时，M1工作在线性区，则121[2(20.7)()()]2outDnOXoutinoutinoutVIRWCVVVVVL+-M1VinVoutR12V•当Vin≥1.3V时，M1工作在饱和区，则211(20.7)2outDnOXoutWVICVRLCopyrightforzhouqn2.7(c)λ=γ=0,VTH=0.7V•当0Vin2.3V时，M1工作在线性区，则121[2(30.7)()()]2outDnOXoutinoutinoutVIRWCVVVVVL+-M1VinVoutR13V•当Vin≥2.3V时，M1工作在饱和区，则211(30.7)2outDnOXoutWVICVRLCopyrightforzhouqn2.7(d)λ=γ=0,VTH=-0.8V•当0Vin1.8V时，M1工作在截止区，则2111(10.8)1.82pOXinWCVRL+-M1VinVoutR11V0outV•M1工作在饱和区边缘的条件为Vout=1.8V，此时假设Vin=Vin1，因而1121.81.8inpOXVWCRL•当1.8VVinVin1时，M1工作在饱和区211(1.8)2outpOXinWVCVRL•当Vin1Vin时，M1工作在线性区211[2(1.8)()()]2outpOXininoutinoutWVCVVVVVRLCopyrightforzhouqn2.9对于图2.46的每个电路，画出IX和VX关于时间的函数曲线图。C1的初始电压等于3V。(a)λ=γ=0,VTH=0.7V，VbVTHVbM1`VxC1Ix当Vb-0.7≤VX≤3V时，M1工作在饱和区21(0.7)2xnOXbWICVL()30xVttxXXxVdQIdtCdVdVIdt21()3(0.7)2XnOXbWVtCVtL当VXVb-0.7时，M1工作在线性区，则21[2(0.7)]2xnOXbXXWICVVVLCopyrightforzhouqn当VXVb-0.7时，M1工作在线性区，则21[2(0.7)]2xnOXbXXWICVVVLxxIdtCdV2122(0.7)xnOXbXXdVWCdtKdtCLVVVK2111[]2(0.7)2(0.7)2(0.7)xxbXXxbXbdVKdtCdVVVVVVVV01()[ln]2(0.7)2(0.7)XbXbVKttVVV0()(0.7)XbVtV02()(0.7)2(0.7)bKttVbXXVVeV02()(0.7)2(0.7)1bbXKttVVVexxdVICdt002(0.7)()22(0.7)()24(0.7)[1]bbKVttbKVttKCVeeC