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diff --git a/Electronic_devices_and_circuits/chapter3.ipynb b/Electronic_devices_and_circuits/chapter3.ipynb new file mode 100755 index 00000000..b37b068d --- /dev/null +++ b/Electronic_devices_and_circuits/chapter3.ipynb @@ -0,0 +1,1540 @@ +{
+ "metadata": {
+ "name": "",
+ "signature": "sha256:cb1edbf7476adce6aba9bf1488bee35026e4b80ac8b3b01d96344eaf38909822"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+ {
+ "cells": [
+ {
+ "cell_type": "heading",
+ "level": 1,
+ "metadata": {},
+ "source": [
+ "\n",
+ "Chapter 3: SMALL SIGNAL MODELS,AMPLIFICATION AND BIASING"
+ ]
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.1,Page number 136"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Variable declaration\n",
+ "beeta=100 #current gain\n",
+ "Ic=2.5 #collector current(mA)\n",
+ "Io=-0.5 #output current(mA) \n",
+ "Rl=2.5 #load resistance(kohm)\n",
+ "\n",
+ "#Calculations\n",
+ "rpi=beeta*(25/Ic) #dynamic resistance(ohms)\n",
+ "Ib=Io/(-beeta) #as Io=-beeta*Ib\n",
+ "Vs=rpi*Ib #signal voltage(V)\n",
+ "Vo=Rl*Io #output voltage(V)\n",
+ "Av=Vo/Vs #voltage gain\n",
+ "Ai=Io/Ib #current gain\n",
+ "\n",
+ "#Results\n",
+ "print\"signal voltage is\",Vs,\"mV\"\n",
+ "print\"current gain is\",Ai\n",
+ "print\"voltage gain is\",round(Av/1E-3)"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "signal voltage is 5.0 mV\n",
+ "current gain is -100.0\n",
+ "voltage gain is -250.0\n"
+ ]
+ }
+ ],
+ "prompt_number": 2
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.2,Page number 139"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "import math\n",
+ "\n",
+ "#Variable declaration\n",
+ "Id=1.6 #drain current(mA)\n",
+ "Vgs=-3 #gate to source voltage(V)\n",
+ "Id1=.4 #drain current(mA)\n",
+ "Vgs1=-4 #gate to source voltage(V) \n",
+ "Vp=-5 #peak voltage(V) by solving equations 1.6=Idss(1+3/Vp)^2 and .4=Idss(1+4/Vp)^2\n",
+ "Idss=10 #small signal drain current(mA) by solving equations 1.6=Idss(1+3/Vp)^2 and .4=Idss(1+4/Vp)^2\n",
+ " \n",
+ "#Calculations\n",
+ "gmo=-(2*Idss)/Vp #transconductance(mS)\n",
+ "gm=gmo*(math.sqrt(Id/Idss)) #transconductance(uS)\n",
+ "gm1=gmo*(math.sqrt(Id1/Idss)) #transconductance(uS) \n",
+ "\n",
+ "#Results\n",
+ "print\"Idss and Vp are\",Idss,\"mA and\",Vp,\"V\"\n",
+ "print\"gmo is\",gmo,\"mS\"\n",
+ "print\"gm at Id is\",round(gm/1E-3),\"and gm at Id1 is\",round(gm1/1E-3),\"uS\""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "Idss and Vp are 10 mA and -5 V\n",
+ "gmo is 4 mS\n",
+ "gm at Id is 1600.0 and gm at Id1 is 800.0 uS\n"
+ ]
+ }
+ ],
+ "prompt_number": 1
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.3,Page number 140"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Variable declaration\n",
+ "gm=1600 #gm(us)\n",
+ "rd=50 #resistance(kohms)\n",
+ "Rl=5 #load resistance(kohms)\n",
+ "\n",
+ "#Calculations\n",
+ "Av=-gm*Rl #Vgs=Vs from circuit model\n",
+ " #Vo=-(gm*Vgs)*Rl\n",
+ " #as Av=Vo/Vs=-gm*Rl \n",
+ "\n",
+ "#Result\n",
+ "print\"voltage gain of the circuit is\",round(Av/1E+3)"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "voltage gain of the circuit is -8.0\n"
+ ]
+ }
+ ],
+ "prompt_number": 5
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.4,Page number 145"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Variable declaration\n",
+ "beta=100. #current gain\n",
+ "rpi=2*10**3 #dynamic resistance(ohms)\n",
+ "rx=500 #resistance(ohms)\n",
+ "ro=250*10**3 #output resistance(ohms)\n",
+ "R1=50*10**3 #resistance(k ohms) \n",
+ "R2=10*10**3 #resistance(k ohms)\n",
+ "Rc=5*10**3 #collector current(k ohms) \n",
+ "Rl=5*10**3. #load current(k ohms)\n",
+ "Rs=1*10**3 #source resistance(k ohms)\n",
+ "\n",
+ "#Calculations\n",
+ "Rb=(R1*R2)/(R1+R2) #equivalent resistance of R1 and R2(kohms)\n",
+ "r=rpi+rx #series resistance of rpi and rx(k ohms) \n",
+ "gm=beta/rpi #transconductance(mS)\n",
+ "Vo=-gm*((Rc*Rl)/(Rc+Rl))*.526 #output voltage(V) as \n",
+ "Av=Vo #voltage gain\n",
+ "Ai=Av*((Rs+((Rb*r)/(Rb+r)))/Rl) #current gain \n",
+ "\n",
+ "#Results\n",
+ "print\"source to load voltage gain is\",Av\n",
+ "print\"source to load current gain is\",Ai,\"(Solution given in the textbook is incorrect)\""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "source to load voltage gain is -65.75\n",
+ "source to load current gain is -38.43745 (Solution given in the textbook is incorrect)\n"
+ ]
+ }
+ ],
+ "prompt_number": 8
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.5,Page number 148"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Variable declaration\n",
+ "beta=100. #current gain\n",
+ "rd=50*10**3 #internal dynamic resistance(ohms\n",
+ "gm=5*10**-3 #transconductance(mS)\n",
+ "R1=50*10**3 #resistance(ohms) \n",
+ "R2=10*10**3 #resistance(ohms)\n",
+ "Rs=10*10**3 #source current(ohms) \n",
+ "Rg=1*10**6. #gate resistance(ohms)\n",
+ "Rd=10*10**3 #drain resistance(ohms)\n",
+ "\n",
+ "#Calculations \n",
+ "Vgs=(Rg/(Rs+Rg)) #gate to source voltage (V) as Vgs=Vs((Rg/(Rs+Rg)) \n",
+ "Av=-Vgs*gm*((rd*Rd)/(rd+Rd)) #voltage gain,Av=Vo/Vs and Vo=-gmVgs(rd||Rd)\n",
+ "Ai=Av*((Rs+Rg)/Rd) #current gain\n",
+ "\n",
+ "#Results\n",
+ "print\"source to load voltage gain is\",round(Av)\n",
+ "print\"source to load current gain is\",round(Ai)"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "source to load voltage gain is -41.0\n",
+ "source to load current gain is -4167.0\n"
+ ]
+ }
+ ],
+ "prompt_number": 4
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.6,Page number 149"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Variable declaration\n",
+ "Rs=500 #collector current(k ohms) \n",
+ "Io=-1*10**-3 #output current(mA) \n",
+ "Rc=5*10**3. #collector resistance(ohms)\n",
+ "hie=2*10**3\n",
+ "hoe=10*10**-6. \n",
+ "hfe=100.\n",
+ "hre=5*10**-4\n",
+ "Rb=50*10**3. #base resistance(ohms)\n",
+ "\n",
+ "#Calculations \n",
+ "Io1=-1/(1+Rc*hoe)*hfe #as Io=-1/(1+Rc*hoe)*hfe*Ib \n",
+ "Ib=-1/Io1 #base current(uA)\n",
+ "Vo=Io*Rc #output voltage(V)\n",
+ "Vi=hie*Ib+Vo*hre #input voltage(V)\n",
+ "Is=Ib+Vi/Rb #source current(ohms)\n",
+ "Ai=Io/Is #current gain\n",
+ "Vs=(Is*Rs)+Vi #source voltage(V)\n",
+ "Av=Vo/Vs #voltage gain\n",
+ "\n",
+ "#Results\n",
+ "print\"source to load voltage gain is\",round(Av/1E-3)\n",
+ "print\"source to load current gain is\",round(Ai/1E-3)"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "source to load voltage gain is -189.0\n",
+ "source to load current gain is -92.0\n"
+ ]
+ }
+ ],
+ "prompt_number": 1
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.7,Page number 153"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Variable declaration\n",
+ "beeta=100. #current gain \n",
+ "Ic=4. #collector current(mA)\n",
+ "Vbe=0.7 #base to emitter voltage(V) \n",
+ "Re=2. #emitter resistance(ohms)\n",
+ "Vcc=32. #supply voltage(V)\n",
+ "abeeta=40. #actual current gain\n",
+ "\n",
+ "#Calculations\n",
+ "Ib=Ic/beeta #base current(mA)\n",
+ "Rb=(Vcc-Vbe-((Ib+Ic)*Re))/Ib #as Vcc=(Ib*Rb)+Vbe+(Ib+Ic)*Re \n",
+ "Ib=(Vcc-Vbe-8)/(Rb+Re) #as Vcc=Rb*Ib+Vbe+(Ib+Ic)*Re\n",
+ "Ic1=abeeta*Ib #collector current(mA)\n",
+ "deltaIc=Ic-Ic1 #change in collector current(mA)\n",
+ "\n",
+ "#Result\n",
+ "print\"change in Ic when beeta=40 is\",deltaIc,\"mA\""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "change in Ic when beeta=40 is 2.4 mA\n"
+ ]
+ }
+ ],
+ "prompt_number": 11
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.8,Page number 155"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Variable declaration\n",
+ "Rb1=36 #base resistance 1(kohms)\n",
+ "Rb2=12 #base resistance 2(kohms)\n",
+ "Rc=4 #emitter resistancce(kohms) \n",
+ "Re=1.8 #emitter resistance(kohms) \n",
+ "Vcc=12 #supply voltage(V)\n",
+ "Vbe=0.7 #base to emitter voltage(V)\n",
+ "\n",
+ "#Calculations\n",
+ "Rb=(Rb1*Rb2)/(Rb1+Rb2) #base resistance(ohms)\n",
+ "Vbb=Vcc*(Rb2/(Rb1+Rb2)) #voltage supply to base(V)\n",
+ " #(10.8*Ib)+(1.8*Ic)=2.3 equation 1...solving -Vbb+RbIb+Vbe+(Ib+IC)Re\n",
+ " #(1.8*Ib)+(5.8*Ic)+Vce=12 equation 2 solving -Vcc+RcIc+Vce+(Ob+Ic)Re\n",
+ "#Part a\n",
+ "beeta=50 #current gain \n",
+ "Ib=2.3/100.8 #(10.8*Ib)+(90*Ib)=2.3 ,using -Vbb+Rb*Ib+Vbe+(Ib+Ic)*Re \n",
+ " #as Ic=50Ib and putting this in equation 1 \n",
+ "Icq=Ib*beeta\n",
+ "Vceq=Vcc-(1.8*Ib)-(5.8*Icq) #from equation 2\n",
+ "\n",
+ "#Part b\n",
+ "beeta=150 #current gain \n",
+ "Ib=2.3/280.8 # (10.8*Ib)+(270*Ib)=2.3,using -Vcc+Rc*Ic+Vce+(Ib+Ic)*Re \n",
+ " #as Ic=150Ib and putting this in equation 1 \n",
+ "Icq1=Ib*beeta \n",
+ "Vceq1=Vcc-(1.8*Ib)-(5.8*Icq1) #from equation 2\n",
+ "\n",
+ "#Results\n",
+ "print\"when beeta increases by 300%,Icq increases by\",round((((Icq1-Icq)/Icq1)*100),1),\"%\"\n",
+ "print\"when beeta increases by 300%, Vceq increases by\",round(((Vceq-Vceq1)/Vceq)*100),\"%\""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "when beeta increases by 300%,Icq increases by 7.1 %\n",
+ "when beeta increases by 300%, Vceq increases by 9.0 %\n"
+ ]
+ }
+ ],
+ "prompt_number": 24
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.9,Page number 156"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Variable declaration\n",
+ "Ic=4 #collector current(mA)\n",
+ "Vce=8 #collector emitter voltage(V) \n",
+ "beeta=100 #current gain \n",
+ "Rb2=24 #base resistance(kohms)\n",
+ "Vbe=0.7 #base to emitter voltage(V)\n",
+ "Rc=4 #collector current(kohm)\n",
+ "Re=2 #emitter resistance(kohms) \n",
+ "Ib=0.04 #base current(mA) \n",
+ "\n",
+ "#Calculations\n",
+ "#Part a\n",
+ "Vcc=(Ic*Rc)+Vce+Ic*Re #from formula Vcc=IcRc+Vce+(Ic+Ib)Re..eq 1\n",
+ "\n",
+ "#Part b\n",
+ "Rb1=Rb2*(Vcc-(Vbe+Ic*Re))/((Vbe+Ic*Re)+Ib) #from eq 1 and also from Vbb= Vcc(Rb2/(Rb1+Rb2))\n",
+ "Rb=(Rb1*Rb2)/(Rb1+Rb2) #base resistance(ohms)\n",
+ "Vbb=(Vcc*Rb2)/(Rb1+Rb2) #supply to base(V)\n",
+ "\n",
+ "#Part c\n",
+ "abeeta=40 #actual current gain\n",
+ "Ib1=((Vbe+Re*Ic)-Vbe)/((1+abeeta)*2+Rb) #from equation Vbb=IbRb+Vbe+(Ic+Ib)Re\n",
+ "Ic1=abeeta*Ib1 #collector gain\n",
+ "\n",
+ "#Results\n",
+ "print\"a)Vcc is\",Vcc,\"V\"\n",
+ "print\"b)values are Rb1:\",round(Rb1,2),\"KOhms,Rb:\",round(Rb,2),\"kohm and Vbb:\",round(Vbb,2),\"V\" \n",
+ "print\"c)actual value of Ic1\",round(Ic1,2),\"mA\""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "a)Vcc is 32 V\n",
+ "b)values are Rb1: 63.98 KOhms,Rb: 17.45 kohm and Vbb: 8.73 V\n",
+ "c)actual value of Ic1 3.22 mA\n"
+ ]
+ }
+ ],
+ "prompt_number": 9
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.10,Page number 158"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Variable declaration\n",
+ "Vcc=10 #supply voltage(V)\n",
+ "Rc=4.7 #collector current(kohms)\n",
+ "Rb=250 #base resistance(kohms)\n",
+ "Re=1.2 #emitter resistance(kohms)\n",
+ "beeta=100 #current gain\n",
+ "Vbe=0.7 #base to emitter voltage(V)\n",
+ "\n",
+ "#Calculations\n",
+ "#Part a\n",
+ "Ib=(Vcc-Vbe)/(Rb+(beeta*(Rc+Re))) #base current(uA)\n",
+ "Ic=beeta*Ib #collector current(mA)\n",
+ "Vce=Vcc-Ic*(Rc+Re) #collector to emitter voltage(V)\n",
+ "#Part b\n",
+ "beeta1=150 #current gain\n",
+ "Ib1=(Vcc-Vbe)/(Rb+(beeta1*(Rc+Re))) #base current(mA)\n",
+ "Ic1=beeta1*Ib1 #collector current(mA)\n",
+ "Vce1=Vcc-Ic1*(Rc+Re) #collector to emitter voltage(V)\n",
+ "deltaIc=((Ic1-Ic)/Ic)*100 #small change in Ic(mA)\n",
+ "deltaVce=((Vce-Vce1)/Vce)*100 #small change in Vce(V)\n",
+ "\n",
+ "#Results\n",
+ "print\"values of Ic is\",round(Ic,2),\"mA and Vce:\",round(Vce,2),\"V\"\n",
+ "print\"values of Ic1 is\",round(Ic1,2),\"mA and Vce1 is\",round(Vce1,2),\"V\"\n",
+ "print\"% change in Ic is\",round(deltaIc,2),\"% and in Vce is\",round(deltaVce,2),\"%\""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "values of Ic is 1.11 mA and Vce: 3.47 V\n",
+ "values of Ic1 is 1.23 mA and Vce1 is 2.75 V\n",
+ "% change in Ic is 11.01 % and in Vce is 20.74 %\n"
+ ]
+ }
+ ],
+ "prompt_number": 12
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.11,Page number 160"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Variable declaration\n",
+ "Id=3 #drain current(mA)\n",
+ "Vds=12 #drain source voltage(V)\n",
+ "Vgs=-3 #gate source voltage(V)\n",
+ "Vdd=36 #drain voltage(V)\n",
+ "Vgg=12 #gate voltage(V)\n",
+ "Rg=12 #gate resistance(Mohms)\n",
+ "\n",
+ "#Calculations\n",
+ "R1=(Rg*Vdd)/Vgg #resistance(Mohms)\n",
+ "R2=(Rg*R1)/(R1-Rg) #resistance(kohms)\n",
+ "Rs=(Vgg-Vgs)/Id #resistance(kohms)\n",
+ "Rd=(Vdd-Vds-Id*Rs)/Id #as Vdd-IdRd-Vds-IdRs\n",
+ "Vgs=-3.6 #consider Vgs increases by 20%\n",
+ "Idnew=(Vgg-Vgs)/Rs #new drain current(mA)\n",
+ "\n",
+ "#Results\n",
+ "print\"value of R1:\",R1,\"MOhm,R2:\",R2,\"Mohms,Rs:\",Rs,\"KOhm and Rd:\",Rd,\"kohms\"\n",
+ "print\"new Id is\",Idnew,\"mA\""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "value of R1: 36 MOhm,R2: 18 Mohms,Rs: 5 KOhm and Rd: 3 kohms\n",
+ "new Id is 3.12 mA\n"
+ ]
+ }
+ ],
+ "prompt_number": 13
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.12,Page number 161"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "from sympy import*\n",
+ "import math\n",
+ "\n",
+ "#Variable declaration\n",
+ "k=0.0002 #device parameter\n",
+ "Vt=4 #thevinin voltage(V) \n",
+ "Vdd=24 #drain voltage(V)\n",
+ "Id0=3 #drain current(mA) \n",
+ "\n",
+ "#Calculations\n",
+ "Vgs=(math.sqrt(Id0/k))+4 #as Id=k(Vgs-Vt)^2\n",
+ "Rd=-(Vgs-Vdd)/Id0 #as Vds=Vdd-IdRd and Vgs=Vds=7.87 \n",
+ "k=0.0003 #device parameter \n",
+ "\n",
+ "Id=symbols('Id')\n",
+ "expr=solve(Id**2-7.5*Id+13.7,Id)\n",
+ "print\"equation has 2 solutions\",expr # putting value of k=0.0003 in eq of Id,\n",
+ "Id1=3.15 # we get Vgs=Vds=24-5.4Id and putting Vgs again in Id we get,\n",
+ " # Id^2-7.5Id+13.7=0\n",
+ " \n",
+ "Idchange=((Id1-Id0)/Id0)*100 #changed Id(mA)\n",
+ "\n",
+ "#Result\n",
+ "print\"change in Id is\",Idchange,\"% increase\""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "equation has 2 solutions [3.14792027106039, 4.35207972893962]\n",
+ "change in Id is 5.0 % increase\n"
+ ]
+ }
+ ],
+ "prompt_number": 18
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.13,Page number 162"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Variable declaration \n",
+ "Vt=2 #threshold voltage(V)\n",
+ "Id=8 #drain current(mA)\n",
+ "Vgs=6. #gate to source voltage(V)\n",
+ "k=0.5 #device parameter\n",
+ "Vdd=24 #drain voltage(V)\n",
+ "Vds=10 #drain to source voltage(V)\n",
+ "\n",
+ "#Calculations\n",
+ "#Part a\n",
+ "Vgs1=4 #gate to source voltage(V) \n",
+ "Id1=k*(Vgs1-Vt)**2 #drain current(mA)\n",
+ "\n",
+ "#Part b\n",
+ "Vgg=3*Vgs1 #gate voltage(V)\n",
+ "R2=(Vdd/Vgg)-1 #resistance(Mohms)\n",
+ "Rs=(Vgg-Vgs1)/2 #source resistance(k ohms)\n",
+ "Rd=(Vdd-Vds-Id1*Rs)/2\n",
+ "\n",
+ "#part c\n",
+ "K=1.5*k #increased by 50%\n",
+ "Vgs2=3.67 #solving 12=Vgs+4Id and Id=0.75(Vgs-2)^2 \n",
+ "Id2=2.08 #drain current when k is increased(mA)\n",
+ "Vds1=Vdd-Id2*(Rd+Rs) #drain to source voltage(V)\n",
+ "\n",
+ "#Results\n",
+ "print\"drain current defined by Vgs=4 and Vds=10 is\",Id1,\"mA\"\n",
+ "print\"value of Rs,Rd,R2 are\",Rs,\"k ohms,\", Rd,\"k ohms,\",R2,\"Mohms resp.\"\n",
+ "print\"actual value of Id and Vds are\",Id2,\"mA,\",Vds1,\"mA and\",Vds,\" V resp.\""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "drain current defined by Vgs=4 and Vds=10 is 2.0 mA\n",
+ "value of Rs,Rd,R2 are 4 k ohms, 3.0 k ohms, 1 Mohms resp.\n",
+ "actual value of Id and Vds are 2.08 mA, 9.44 mA and 10 V resp.\n"
+ ]
+ }
+ ],
+ "prompt_number": 9
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.14,Page number 166"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Variable declaration\n",
+ "Ic=10 #collector current(mA)\n",
+ "beeta=100 #current gain\n",
+ "Vbe=0.7 #base to emitter voltage(V)\n",
+ "Vcc=10 #supply voltage(V) \n",
+ "\n",
+ "#Calculations\n",
+ "#Part a\n",
+ "R=(beeta*(Vcc-Vbe))/((beeta+2)*Ic) #resistance(k ohms) \n",
+ "beeta1=200 #current gain\n",
+ "Ic1=(beeta1/(beeta1+2))*((Vcc-Vbe)/R) #collector current(mA)\n",
+ "Icchange=((Ic-Ic1)/Ic) #change in collector current(mA) \n",
+ "\n",
+ "#Part b\n",
+ "Ic2=0.1 #collector current(mA)\n",
+ "R1=(beeta*(Vcc-Vbe))/((beeta+2)*Ic) #resistance(k ohms)\n",
+ "Ic3=(beeta1/(beeta1+2))*((Vcc-Vbe)/R1) #collector current(mA)\n",
+ "Icchange1=((Ic2-Ic3)/Ic2) #change in collector current(mA)\n",
+ "\n",
+ "#Results\n",
+ "print\"% change in Ic is\",round(Icchange,1),\"% increase\"\n",
+ "print\"% change in Ic is\",round(Icchange1,1),\"% increase\""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "% change in Ic is 1.0 % increase\n",
+ "% change in Ic is 1.0 % increase\n"
+ ]
+ }
+ ],
+ "prompt_number": 30
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.15,Page number 167"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Variable declaration\n",
+ "Vcc=6 #supply voltage(V)\n",
+ "R=1.2 #resistance(k ohms)\n",
+ "Vbe=0.7 #base to emitter voltage(V) \n",
+ "beeta=100. #current gain\n",
+ "\n",
+ "#Calculations\n",
+ "#Part a\n",
+ "Ir=(Vcc-Vbe)/R #current(mA)\n",
+ "I=(beeta/(beeta+3))*Ir #current(mA)as transistors are identiical,I=Ie\n",
+ "\n",
+ "#Result\n",
+ "print\"load current I is\",round(I,2),\"mA\""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "load current I is 4.29 mA\n"
+ ]
+ }
+ ],
+ "prompt_number": 34
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.16,Page number 171"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "import math \n",
+ "\n",
+ "#Variable declaration\n",
+ "Idss=10 #drain current for zero bias(mA)\n",
+ "Vp=-4 #peak voltage(V)\n",
+ "Idq=Id=2.5 #quienscent drain current(mA)\n",
+ "Vdd=24 #voltage drain drain(V)\n",
+ "Vgg=4 #gate voltage(V)\n",
+ "R1=22 #resistance(Mohms)\n",
+ "\n",
+ "#Calculations\n",
+ "#Part a\n",
+ "Vgs=Vp*(1-(math.sqrt(Id/Idss))) #solving Id=Idss(1-Vgs/Vp)^2\n",
+ "Rs=(Vgg-Vgs)/Id #as Vgg-Vgs-IdRs=0 ,Id=Is \n",
+ "Rd=2.5*Rs #given\n",
+ "R2=(Vgg*R1)/(R1-Vgg) #from Vgg=(R1*R2)/(R1+R2)\n",
+ "\n",
+ "#Part b\n",
+ "gmo=-(2*Idss)/Vp #transconductance(mS)\n",
+ "gm=gmo*(math.sqrt(Id/Idss)) #transconductance(mS)\n",
+ "\n",
+ "#Part c\n",
+ "Av=-gm*Rd #voltage gain\n",
+ "\n",
+ "#Results\n",
+ "print\"values of Rs:\",Rs,\"Kohms,Rd:\",Rd,\"k ohms and R2 is\",round(R2,1),\"M ohms\"\n",
+ "print\"value of gm is\",gm,\"mS and gmo is\",gmo,\"mS\"\n",
+ "print\"voltage amplification is\",Av"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "values of Rs: 2.4 Kohms,Rd: 6.0 k ohms and R2 is 4.0 M ohms\n",
+ "value of gm is 2.5 mS and gmo is 5 mS\n",
+ "voltage amplification is -15.0\n"
+ ]
+ }
+ ],
+ "prompt_number": 15
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.17,Page number 174"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "import math\n",
+ "\n",
+ "#Variable declaration\n",
+ "beeta=98. #current gain\n",
+ "rpi=1.275 #dynamic resistance(k ohms)\n",
+ "Rb=220. #base resistance(k ohms)\n",
+ "Re=3.3 #emitter resistance(k ohms)\n",
+ "Vcc=12. #supply voltage(V)\n",
+ "Vbe=0.7 #base to emitter voltage(V)\n",
+ "\n",
+ "#Calculations\n",
+ "#Part a\n",
+ "x=rpi/(1+beeta)\n",
+ "Av=Re/(Re+x) #voltage gain\n",
+ "\n",
+ "#Part b\n",
+ "Zb=rpi+(1+beeta)*Re #impedance(k ohms)\n",
+ "Zi=(Zb*Rb)/(Zb+Rb) #input impedance(k ohms)\n",
+ "Zo=(Re*x)/(Re+x) #output impedance(k ohms)\n",
+ "\n",
+ "#Part c\n",
+ "Ib=(Vcc-Vbe)/(Rb+(Re*(1+beeta))) #as Ie=(1+beeta)*Ib\n",
+ "Ic=beeta*Ib #collector current(mA)\n",
+ "rpi=beeta*(25/Ic) #dynamic resistance(k ohms)\n",
+ "\n",
+ "#Results\n",
+ "print\"voltage gain is\",round(Av,3)\n",
+ "print\"input impedance is\",round(Zi,1),\"KOhm and output impedance is\",round((Zo/1E-3),1),\"ohms\"\n",
+ "print\"value of Ic is\",round(Ic,3),\"mA\"\n",
+ "print\"value of rpi is\",round((rpi/1E+3),3),\"k ohms\""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "voltage gain is 0.996\n",
+ "input impedance is 131.7 KOhm and output impedance is 12.8 ohms\n",
+ "value of Ic is 2.026 mA\n",
+ "value of rpi is 1.21 k ohms\n"
+ ]
+ }
+ ],
+ "prompt_number": 2
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.18,Page number 176"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "from sympy import*\n",
+ "import math\n",
+ "\n",
+ "#Variable declaration\n",
+ "Idss=16 #drain current bias to zero(mA) \n",
+ "Vp=-4 #pinch off voltage(V) \n",
+ "Rg=1 #gate resistance(ohms)\n",
+ "Rs=2.2 #sourse resistance(ohm)\n",
+ "Vdd=9 #drain drain voltage(V)\n",
+ "\n",
+ "#Calculations\n",
+ "#Part a\n",
+ "#Id=Idss*(1-(Vgs/Vp))**2\n",
+ "# putting value of Vgs=2.2*Id inequation of Id,we get\n",
+ "#Id**2-3.84Id+3.31 \n",
+ "\n",
+ "Id=symbols('Id')\n",
+ "expr=solve(Id**2-3.84*Id+3.31,Id)\n",
+ "print expr\n",
+ "Id1=1.3 \n",
+ "Vgs=-Id1*Rs #gate to source voltage(V)\n",
+ "gm0=-(2*Idss)/Vp #transconductance(mS)\n",
+ "gm=gm0*(1-(Vgs/Vp)) #transconductance(mS) \n",
+ "rm=1/gm #transresistance(k ohms) \n",
+ "Av=(Rs*gm)/(1+(Rs*gm)) #voltage gain\n",
+ "\n",
+ "#Part b\n",
+ "Zi=Rg #input impedance(Mohms)\n",
+ "Zo=(Rs*rm)/(Rs+rm) #output impedance(ohms)\n",
+ "\n",
+ "#Results\n",
+ "print\"voltage gain is\",round(Av,3)\n",
+ "print\"input and output impedences are\",Zi,\"Mohms and\",round((Zo/1E-3),1),\"ohms\""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ " [1.30648553399288, 2.53351446600712]\n",
+ "voltage gain is 0.834\n",
+ "input and output impedences are 1 Mohms and 365.7 ohms\n"
+ ]
+ }
+ ],
+ "prompt_number": 4
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.19,Page number 182"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "import math\n",
+ "\n",
+ "#Variable declaration\n",
+ "Re=0.56 #emitter resistance(k ohms)\n",
+ "beta=1600 #current gain\n",
+ "R1=110 #resistance(k ohms)\n",
+ "R2=330 #resistance(k ohms)\n",
+ "\n",
+ "#Calculations\n",
+ "#Part a\n",
+ "Av1=Re*(beta+1) #voltage gain\n",
+ "\n",
+ "#part b\n",
+ "Rb=(R1*R2)/(R1+R2) #base resistance(k ohms)\n",
+ "Vs=(1.56/(Re*(beta+1)))+1 #source voltage(V) \n",
+ "Avs=1/Vs\n",
+ "\n",
+ "#part c\n",
+ "R=1+(1+beta)*Re #resistance presented to Ib\n",
+ "I=Rb/(Rb+R) #I=Ib/Ii \n",
+ "Ai=(1+beta)*I #current gain\n",
+ "\n",
+ "#part d\n",
+ "Rl=10*10**3 #load resistance(ohm)\n",
+ "Re1=(Re*Rl)/(Re+Rl) #emitter resistance(k ohms)\n",
+ "R1=1+(1+beta)*Re1 #resistance presented to Ib(k ohms)\n",
+ "I1=Rb/(Rb+R1) #I1=Ib/Ii\n",
+ "Ai1=(beta+1)*I1 #current gain\n",
+ "Av2=Re1*(1+beta) #voltage gain\n",
+ "\n",
+ "#Results\n",
+ "print\"a)voltage gain is\",Av1\n",
+ "print\"b)Avs is\",round(Avs,2)\n",
+ "print\"c)Ai is\",round(Ai,2)\n",
+ "print\"when output Vo1 feeds a load of 10 k ohms Ai is\",round(Ai1),\"and Av2 is\",round(Av2)"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "a)voltage gain is 896.56\n",
+ "b)Avs is 1.0\n",
+ "c)Ai is 134.02\n",
+ "when output Vo1 feeds a load of 10 k ohms Ai is 134.0 and Av2 is 897.0\n"
+ ]
+ }
+ ],
+ "prompt_number": 1
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.20,Page number 184"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Variable declaration\n",
+ "beeta1=120. #current gain\n",
+ "beeta2=160. #current gain\n",
+ "Vcc=18 #supply voltage(V)\n",
+ "Rc=0.1 #collector resistance(ohms)\n",
+ "Rb=2*10**3. #base resistance(ohms)\n",
+ "Vbe=0.7 #base to emitter voltage(V)\n",
+ "\n",
+ "#Calculations\n",
+ "Ib1=(Vcc-Vbe)/(Rb+(beeta1*beeta2*Rc))#base current(uA)\n",
+ "Ib2=beeta1*Ib1 #base current(mA)\n",
+ "Ie1=(beeta1+1)*Ib1 #emitter current(mA)\n",
+ "Ic=Ie1+(beeta2*Ib2) #collector current(mA)\n",
+ "Vo=Vcc-(Ic*Rc) #output voltage(V)\n",
+ "Vi=Vo-Vbe #input voltage(V)\n",
+ "\n",
+ "#Results\n",
+ "print\"dc biased current is\",round(Ic,1),\"mA\"\n",
+ "print\"output voltage\",round(Vo,2),\"V\"\n",
+ "print\"input voltage\",round(Vi,2),\"V\""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "dc biased current is 85.3 mA\n",
+ "output voltage 9.47 V\n",
+ "input voltage 8.77 V\n"
+ ]
+ }
+ ],
+ "prompt_number": 13
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.21,Page number 191"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "import math\n",
+ "\n",
+ "#Variable declaration\n",
+ "deltaId=2. #change in Id(mA)\n",
+ "deltaVgs=1. #change in Vgs(V)\n",
+ "deltaVds=5. #change in Vds(V)\n",
+ "Idss=10. #drain current biased to zero(mA)\n",
+ "Id=5. #drain current(mA)\n",
+ "Vp=-6. #pinch off voltage(V)\n",
+ "\n",
+ "#Calculations\n",
+ "#Part a\n",
+ "gm=(deltaId)/(deltaVgs) #transconductance(mS)\n",
+ "rds=(deltaVds)/(deltaId) #resistance(k ohms)\n",
+ "gm0=-(2*Idss)/Vp #transconductance(mS)\n",
+ "gm=gm0*(math.sqrt(Id/Idss)) #transconductance(mS)\n",
+ "\n",
+ "#Part b\n",
+ "R1=4.5 #resistance(k ohms)\n",
+ "R2=2 #resistance(k ohms)\n",
+ "Av=gm*((R1*R2)/(R1+R2)) #voltage gain\n",
+ "\n",
+ "#Results\n",
+ "print\"drain current biased to zero is\",Idss,\"mA and pinch off voltage is\",Vp,\"V\"\n",
+ "print\"value of gm and rds are\",round(gm,2),\"mS and\",rds,\"k ohms\"\n",
+ "print\"small signal amplifier gain is\",round(Av,2)"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "drain current biased to zero is 10.0 mA and pinch off voltage is -6.0 V\n",
+ "value of gm and rds are 2.36 mS and 2.5 k ohms\n",
+ "small signal amplifier gain is 3.26\n"
+ ]
+ }
+ ],
+ "prompt_number": 4
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.22,Page number 193"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "import math\n",
+ "\n",
+ "#Variable declaration\n",
+ "Idson=0.2\n",
+ "Vgs=5 #gate to source voltage(V)\n",
+ "Vdd=12 #drain voltage(V)\n",
+ "Vt=2 #thevinine voltage(V)\n",
+ "R1=100. #resistance(k ohms) \n",
+ "R2=100. #resistance(k ohms) \n",
+ "Rd=30 #drain resistance(K ohms)\n",
+ "Rs=6 #source resistance(k ohms)\n",
+ "deltaVdd=0.3 #change in Vdd(V)\n",
+ "rds=50 #internal drain to source resistance()\n",
+ "\n",
+ "#Calculations\n",
+ "#Part a\n",
+ "k=Idson/((Vgs-Vt)**2) #device parameter\n",
+ "Vgg=Vdd*(R1/(R1+R2)) #gate voltage(V)\n",
+ "Vgs=4.89 #gate to source voltage(V)\n",
+ "Id=k*(Vgs-Vt)**2 #drain current(mA)\n",
+ "Vds=Vdd-((Rd+Rs)*Id) #drain to source voltage(V)\n",
+ "gm=2*(math.sqrt(k*Id)) #transconductance(mS)\n",
+ "deltaVgg=deltaVdd*(R2/(R1+R2)) #change in Vgg(V)\n",
+ "\n",
+ "vgs=0.105 #as vgs=0.15-6id where id=u*vgs/(rds+Rs+Rd)=0.74vgs after solving\n",
+ "id= 0.074*vgs*10**3\n",
+ "\n",
+ "#Results\n",
+ "print\"id is\",id,\"uA\""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "id is 7.77 uA\n"
+ ]
+ }
+ ],
+ "prompt_number": 5
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.23,Page number 194"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "import math\n",
+ "\n",
+ "#Variable declaration\n",
+ "deltaId=1 #change in Id(mA)\n",
+ "deltaVgs=0.75 #change in Vgs(V) \n",
+ "rd=100 #internal drain resistance(k ohms)\n",
+ "Rd=100 #drain resistance(k ohms)\n",
+ "Vgs=2 #as Vgs= 2sinwt \n",
+ "\n",
+ "#Calculations\n",
+ "gm=(deltaId)/(deltaVgs) #transconductance(m) \n",
+ "Vo=-gm*Vgs*((rd*Rd)/(rd+Rd)) # as Vi=2sin(w*t)\n",
+ "\n",
+ "#Results\n",
+ "print\"value of Vo is\",round(Vo),\"*sinwt mV\""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "value of Vo is -133.0 *sinwt mV\n"
+ ]
+ }
+ ],
+ "prompt_number": 50
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.24,Page number 195"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Finding resistance\n",
+ "\n",
+ "#Variable declaration\n",
+ "Rd=4 #drain resistance(ohms)\n",
+ "Rs=2.5 #ource resistance(ohms) \n",
+ "R1=200*10**3 #resistance(ohms)\n",
+ "R2=100*10**3 #resistance(ohms)\n",
+ "gm=2.5 #transconductance(mS)\n",
+ "rd=60 #internal drain resistance(ohms)\n",
+ "\n",
+ "#Calculations\n",
+ "#Part b\n",
+ "Ro=Rs/(1+(((1+gm*rd)*Rs)/(rd+Rd))) #output resistance(ohms)\n",
+ "\n",
+ "#Part c\n",
+ "Rd1=0 #drain resistance\n",
+ "Ro1=Rs/(1+(((1+gm*rd)*Rs)/rd)) #output resistance(ohms)\n",
+ "\n",
+ "#Results\n",
+ "print\"value of Ro is\",round(Ro/1E-3),\"ohms\"\n",
+ "print\"value of Ro1 is\",round(Ro1/1E-3),\"ohms\""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "value of Ro is 362.0 ohms\n",
+ "value of Ro1 is 343.0 ohms\n"
+ ]
+ }
+ ],
+ "prompt_number": 60
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.25,Page number 196"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Variable declaration\n",
+ "beeta=100 #current gain factor\n",
+ "Vbe=0.7 #base to emitter voltage(V)\n",
+ "Rb=250 #base resistance(k ohms)\n",
+ "Vee=10 #emitter voltage(V)\n",
+ "Re=1 #emitter resistance(k ohms)\n",
+ "\n",
+ "#Calculations\n",
+ "Ib=(Vee-Vbe)/(Rb+1+beeta) # solving Rb*Ib+Vbe+(Ic+Ib)=Vee and putting Ic+Ib=(1+beeta)Ib\n",
+ "Ic=beeta*Ib #collector current(mA)\n",
+ "rpi=beeta*(25/Ic) #dynamic resistance(ohms) \n",
+ "Vi=(rpi*Ib)+(1+beeta)*Re*Ib #input voltage(V)\n",
+ "Ri=Vi/Ib #input resistance(k ohms)\n",
+ "\n",
+ "#Results\n",
+ "print\"value of Ri is\",round((Ri/1E+1),1),\"K ohms\""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "value of Ri is 104.5 K ohms\n"
+ ]
+ }
+ ],
+ "prompt_number": 35
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.26,Page number 197"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Variable declaration\n",
+ "beeta=125 #current gain\n",
+ "gm=35 #transconductance(mS)\n",
+ "Re=4 #emitter resistance(k ohms)\n",
+ "Rb=1.5 #base resistance(k ohms)\n",
+ "\n",
+ "#Calculations\n",
+ "#Part a\n",
+ "rpi=beeta/gm #dynamic resistance(k ohms)\n",
+ "Ri=rpi+((1+beeta)*Re) #input resistance(k ohms) \n",
+ "Ro=((Rb+rpi)*Re)/((Rb+rpi)+((1+beeta)*Re)) #output resistance(ohms) as Ro=Vo/Isc\n",
+ "\n",
+ "#Part b \n",
+ "f=((1+beeta)*Re)/(Rb+rpi+((1+beeta)*Re)) #transfer function\n",
+ "\n",
+ "#Results\n",
+ "print\"value of Ri is\",Ri,\"K ohms and Ro is\",round(Ro,4),\"k\"\n",
+ "print\"transfer function is\",round(f,2)"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "value of Ri is 507 K ohms and Ro is 0.0354 k\n",
+ "transfer function is 0.99\n"
+ ]
+ }
+ ],
+ "prompt_number": 6
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.28,Page number 199"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Variable declaration \n",
+ "Vcc=16 #supply voltage(V)\n",
+ "Vc=12 #collector voltage(V)\n",
+ "Ic=8 #collector current(mA)\n",
+ "Ic1=12 \n",
+ "deltaIc=2000 #collector current(uA)\n",
+ "deltaVce=4 #collector emitter voltage(Vce) \n",
+ "deltaIb=20 #base current(mA) \n",
+ "Rl=2. #load reistance(k ohms) \n",
+ "\n",
+ "#Calculations\n",
+ "hfe=(deltaIc)/(deltaIb)\n",
+ "hoe=(deltaIc)/(deltaVce)\n",
+ "Rdc=Vcc/Ic #dc resistance(k ohms)\n",
+ "Rac=Vc/Ic1 #ac resistance(k ohms)\n",
+ "Re=Rdc-Rac #emitter resistance(k ohms)\n",
+ "Rac1=(Rac*Rl)/(Rac+Rl) #for load of 2kohms, Rc=Rac\n",
+ "Icq=Vcc/(Rac1+Rdc) #Ic at operatingpoint(mA) \n",
+ "Vceq=Vcc-(Icq*Rdc) #Vc at operating point(V)\n",
+ "\n",
+ "#Results\n",
+ "print\"value of hfe and hoe are\",hfe,\"uS and\",hoe,\"uS\"\n",
+ "print\"value Rc and Re are\",Rac,\"k ohms and\",Re,\"k ohms resp.\"\n",
+ "print\"value of Icq and Vce\",Icq,\"mA and\",Vceq,\"V resp.\""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ " value of hfe and hoe are 100 uS and 500 uS\n",
+ "value Rc and Re are 1 k ohms and 1 k ohms resp.\n",
+ "value of Icq and Vce 6.0 mA and 4.0 V resp.\n"
+ ]
+ }
+ ],
+ "prompt_number": 8
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.29,Page number 200"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Variable declaration\n",
+ "hfe=120 #current gain\n",
+ "r1=1.5 #resistance(k ohms)\n",
+ "Vi=1 #input voltage(V) \n",
+ "hoe=50*10**-3 #output conductance with input open circuited\n",
+ "Rs=2 #source resistance(k ohms)\n",
+ "Vbe=0.7 #base to emitter voltage(V)\n",
+ "Vcc=10 #supply voltage(V)\n",
+ "r3=0.33 #resistance(k ohms)\n",
+ "r4=5.8 #rsistance(k ohms) \n",
+ "r5=27 #rsistance(k ohms) \n",
+ "hoe=50*10**-3 #output conductance with input open circuited\n",
+ " \n",
+ "#Calculations\n",
+ "#Part a\n",
+ "Vbb=Vcc*(r4/(r4+r5)) #voltage to bae(V)\n",
+ "Rb=(r5*r4)/(r5+r4) # as Vbb-Vbe=RbIb+(hfe+1)Ib*R,here hfe=beeta\n",
+ "ib=(Vbb-Vbe)/(Rb+(hfe+1)*r3) #instantaneous base current(mA)\n",
+ "hie=(0.02/ib)*10**3 \n",
+ "Ib=Vi/hie #base current(mA)\n",
+ "h=hfe*Ib\n",
+ "Avo=-h*r1 #voltage gain\n",
+ "\n",
+ "#Part b\n",
+ "r=1/hoe #resistance(k ohms)\n",
+ "R1=(r*r1)/(r+r1) #resitance(k ohms)\n",
+ "R=(R1*Rs)/(R1+Rs) #resistance(k ohms)\n",
+ "Ib1=1/(Rs+R) #base current(mA)\n",
+ "h1=hfe*Ib1\n",
+ "Avl=-h1*R #voltage gain\n",
+ "\n",
+ "#Results\n",
+ "print\"hie and Avo are\",round(hie),\"and\",round((Avo/1E-3),1)\n",
+ "print\"Avl is\",round(Avl,2)"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "hie and Avo are 837.0 and -215.1\n",
+ "Avl is -34.95\n"
+ ]
+ }
+ ],
+ "prompt_number": 20
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.30,Page number 201"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Variable declaration\n",
+ "Rl=20 #load resistance(ohms)\n",
+ "Vcc=30 #supply voltage(V)\n",
+ "beeta=150 #current gain \n",
+ "Re=2200 #emitter resistance(ohms) \n",
+ "Rb=350 #base resistance(k ohms) \n",
+ "Vbe=0.7 #base to emitter voltage(V)\n",
+ "Is=10**-3 #source current(A) \n",
+ "r1=2000 #resistance(ohms)\n",
+ "\n",
+ "#Calculations\n",
+ "Ib=(Vcc-Vbe)/(Rb+(1+beeta)*Re)#base current(uA)\n",
+ "Ic=beeta*Ib #collector current(mA)\n",
+ "rpi=beeta*(25/Ic) #dynamic resistance(ohms) \n",
+ "R=(Re*Rl)/(Re+Rl) #resistance(ohms) \n",
+ "Ib1=17.95 #round the base emitter(as Rb>>2 kohms,it it ignored)\n",
+ "Vl=(beeta+1)*Ib1*R #load voltage(V)\n",
+ "Avl=Vl #Voltage gain\n",
+ "Il=Vl/Rl #load current(A)\n",
+ "Ail=Il/Is #current gain\n",
+ "\n",
+ "#Results\n",
+ "print\"overall voltage gain is\",round((Avl/1E+3),2)\n",
+ "print\"overall current gain is\",round(Ail/1E+3)"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "overall voltage gain is 51.5\n",
+ "overall current gain is 2575.0\n"
+ ]
+ }
+ ],
+ "prompt_number": 34
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 3.31,Page number 202"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Variable declaration\n",
+ "Vcc=15 #supply voltage(V)\n",
+ "beeta=30 #current gain \n",
+ "R=.47 #emitter resistance(ohms) \n",
+ "Vbe=0.7 #base to emitter voltage(V)\n",
+ "Vo=5 #output voltage(V)\n",
+ "\n",
+ "#Calculations\n",
+ "Vbb=Vcc/2 #base voltage(V)\n",
+ "'''\n",
+ "Vbb=(R1/2)*Ib+Vbe*2+(30Ib+Ic2)*R\n",
+ "Ic2=beeta*30Ib,so\n",
+ "Ic2=30*30Ib=900Ib\n",
+ "Vbb=(R1/2)*Ib+Vbe*2+(30+900)*R*Ib....(i)\n",
+ "(R1/2)*Ib+437*Ib=6.1.......(ii)\n",
+ "0.47*930Ib=5 #output voltage is given like this\n",
+ "\n",
+ "'''\n",
+ "Ib=Vo/(R*930) #from equation(i)\n",
+ "\n",
+ "'''\n",
+ "substituting value of Ibin eq(ii) we get\n",
+ "\n",
+ "'''\n",
+ "R1=((6.1-4.98)/0.0114)*2 #resistance(k ohms) \n",
+ "#Results\n",
+ "print\"value of R1 is\",round(R1),\"K ohms\""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "value of R1 is 196.0 K ohms\n"
+ ]
+ }
+ ],
+ "prompt_number": 9
+ }
+ ],
+ "metadata": {}
+ }
+ ]
+}
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