{
"metadata": {
"name": ""
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 6 : Field Effect Transistors"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 6.1, Page No. 184"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# drain resistance transconductance and amplification factor\n",
"\n",
"import math\n",
"from array import array\n",
"#Variable declaration\n",
"Vgs=array('d', [0.0, 0.0, 0.3]) #in V\n",
"Vds=array('d',[5.0, 10.0, 10.0]) #in V\n",
"Id=array('d',[8.0, 8.2, 7.6]) #in mA\n",
"\n",
"#Calcualtions\n",
"dVds=Vds[1]-Vds[0] #in V\n",
"dId=Id[1]-Id[0] #in mA\n",
"rd=(dVds/dId) #in kilo-ohm\n",
"dVgs=Vgs[2]-Vgs[1] #in V\n",
"dId1=Id[1]-Id[2] #in mA\n",
"gm=dId1/dVgs #in mA/volt\n",
"mu=gm*rd #A/V\n",
"\n",
"#Result\n",
"print(\"(i) A.C. Drain resistance is ,(kilo-ohm)= %.f\"%rd)\n",
"print(\"(ii) Transconductance is ,(mS) = %.f\"%gm)\n",
"print(\"(iii) Amplification factor is , = %.f\"%mu)\n",
"#Transconductance and Amplification factor are calculated wrong in the textbook"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"(i) A.C. Drain resistance is ,(kilo-ohm)= 25\n",
"(ii) Transconductance is ,(mS) = 2\n",
"(iii) Amplification factor is , = 50\n"
]
}
],
"prompt_number": 4
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 6.2, Page No. 184"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# mutual conductance\n",
"\n",
"import math\n",
"#Variable declaration\n",
"I1=1.0 # in mA\n",
"I2=1.2 # in mA\n",
"V1=-3.0 # in V\n",
"V2=-2.9 # in V\n",
"\n",
"#Calculations\n",
"del_ID=(I2-I1)\n",
"del_VGS=V2-V1 # in V\n",
"gm=del_ID/del_VGS\n",
"\n",
"#Result\n",
"print(\"mutual conductance,gm(mS) = %.f\"%gm)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"mutual conductance,gm(mS) = 2\n"
]
}
],
"prompt_number": 15
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 6.3, Page No. 185"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# pinch off voltage\n",
"\n",
"import math\n",
"#Variable declaration\n",
"a=5.6*10**-6/2 # channel width in m\n",
"epsilon0=8.86*10**-12 # in F/m\n",
"epsilon=12*epsilon0 # in F/m\n",
"Nd=10**21 # in m^-3\n",
"e=1.6*10**-19 # in V\n",
"\n",
"#Calculations\n",
"Vp=e*Nd*a**2/(2*epsilon);\n",
"\n",
"#Result\n",
"print(\"Pinch off voltage,Vp(V) = %.1f\"%Vp)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Pinch off voltage,Vp(V) = 5.9\n"
]
}
],
"prompt_number": 17
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 6.4, Page No. 185"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# ID gm and gmo\n",
"\n",
"import math\n",
"#Variable declaration\n",
"I_DES=8.7 # in mA\n",
"V1=-3.0 # in V\n",
"V_GS=-1.0 # in V\n",
"\n",
"\n",
"#Calculations\n",
"gmo=-(2*I_DES/V1)\n",
"ID=I_DES*(1-(V_GS/V1))**2\n",
"gm=gmo*(1-(V_GS/V1));\n",
"\n",
"#Result\n",
"print(\"(i). ID(mA) = %.3f\"%(math.floor(ID*1000)/1000))\n",
"print(\"(ii). gmo(mS) = %.1f\"%gmo)\n",
"print(\"(iii).gm(mA) = %.3f\"%(math.floor(gm*1000)/1000))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"(i). ID(mA) = 3.866\n",
"(ii). gmo(mS) = 5.8\n",
"(iii).gm(mA) = 3.866\n"
]
}
],
"prompt_number": 2
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 6.5, Page No. 186"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# Vgs\n",
"\n",
"import math\n",
"#Variable declaration\n",
"ID=3.0 # in mA\n",
"I_DSS=9.0 # in mA\n",
"Vp=-4.5 # in V\n",
"\n",
"#Calculations\n",
"Vgs=-Vp*(math.sqrt(ID/I_DSS)-1)\n",
"\n",
"\n",
"#Result\n",
"print(\"Vgs(V) = %.1f\"%Vgs)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Vgs(V) = -1.9\n"
]
}
],
"prompt_number": 25
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 6.6, Page No. 196"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# voltage amplification\n",
"\n",
"import math\n",
"#Variable declaration\n",
"gm=3 #Transconductance in mS\n",
"rl=10 #load resistance in kilo-ohm\n",
"\n",
"#Calculations\n",
"av=gm*rl\n",
"#Result\n",
"print(\"the voltage aplification is ,= %.f\"%av)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"the voltage aplification is ,= 30\n"
]
}
],
"prompt_number": 27
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 6.7, Page No. 196"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# output voltage\n",
"\n",
"import math\n",
"#Variable declaration\n",
"Rl=20.0 #in kilo-ohm\n",
"Rs=1.0 #in kilo-ohm\n",
"Rg=1.0 #in M-ohm\n",
"Cs=25.0 #in micro-F\n",
"mu=20.0 #amplification factor\n",
"rd=100.0 #in kilo-ohm\n",
"vi=2.0 #in V\n",
"f=1.0 #in kilo-Hz\n",
"\n",
"#Calculations\n",
"Xc=((1/(2*math.pi*f*10**3*Cs*10**-6)))\n",
"A=((mu*Rl*10**3)/((rd+Rl)*10**3))\n",
"Vo=A*vi\n",
"\n",
"#Result\n",
"print(\"amplifier output signal voltage is ,(V)= %.2f\"%(math.floor(Vo*100)/100))\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"amplifier output signal voltage is ,(V)= 6.66\n"
]
}
],
"prompt_number": 3
}
],
"metadata": {}
}
]
}