{
"metadata": {
"name": ""
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 10 : FET biasing"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 10.1, Page No 381"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"#initialisation of variables\n",
"\n",
"Vdd=22.0\n",
"Rd=2.0*10**3\n",
"\n",
"#Calculations\n",
"print(\"when Id=0\")\n",
"Id=0\n",
"Vds=Vdd-Id*Rd\n",
"print('at point A Vds = %.2f V' %Vds)\n",
"Vds=0\n",
"Id=Vdd/Rd\n",
"\n",
"#Results\n",
"print(\"when Vds=0\")\n",
"print('at point A Id = %.2f mA' %(Id*10**3))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"when Id=0\n",
"at point A Vds = 22.00 V\n",
"when Vds=0\n",
"at point A Id = 11.00 mA\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 10.4, Page No 387"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"#initialisation of variables\n",
"\n",
"Idss=8.0*10**-3\n",
"Vpmax=6.0\n",
"Vgs=2.3\n",
"Vgsmax=6\n",
"\n",
"#Calculations\n",
"Id=Idss*(1-(Vgs/Vgsmax))**2\n",
"Idss=4*10**-3\n",
"Vp=3\n",
"Idmin=Idss*(1-(Vgs/Vp))**2\n",
"\n",
"#Results\n",
"print('at point A Idmin = %.2f mA' %(Idmin*10**3))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"at point A Idmin = 0.22 mA\n"
]
}
],
"prompt_number": 2
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 10.6 Page No 393"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"#initialisation of variables\n",
"Vdd=25.0\n",
"R2=1.0*10**6\n",
"R1=3.8*10**6\n",
"Rs=2.5*10**3\n",
"Rd=2.5*10**3\n",
"\n",
"#Calculations\n",
"Vg=(Vdd*R2)/(R1+R2)\n",
"print(\"when Id=0\")\n",
"Id=0\n",
"Vgs=Vg-Id*Rs\n",
"print(\" plot point A at Id=0\")\n",
"print('at point A Vds = %.2f A/s' %Vds)\n",
"Vgs=0\n",
"Id=Vg/Rs\n",
"print(\" plot point B Vgs=0\")\n",
"print('at point A Id = %.2f A/s' %Id)\n",
"Idmax=3*10**-3\n",
"Idmin=2.3*10**-3\n",
"Vdsmin=Vdd-Idmax*(Rd+Rs)\n",
"Vdsmax=Vdd-Idmin*(Rd+Rs)\n",
"\n",
"#Results\n",
"print('The value of Vdsmax = %.2f V' %(Vdsmax))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"when Id=0\n",
" plot point A at Id=0\n",
"at point A Vds = 0.00 A/s\n",
" plot point B Vgs=0\n",
"at point A Id = 0.00 A/s\n",
"The value of Vdsmax = 13.50 V\n"
]
}
],
"prompt_number": 3
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 10.7, Page No 401"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"#initialisation of variables\n",
"\n",
"Id=3.0*10**-3\n",
"Vgs=-2.3\n",
"Vdsmin=10.0\n",
"Vdd=25.0\n",
"Vgsoff=-6\n",
"Idss=8.0*10**-3\n",
"\n",
"#Calculations\n",
"Vgs=Vgsoff*(1-math.sqrt(Id/Idss))\n",
"Rd=(Vdd-Vdsmin)/Id\n",
"\n",
"#Results\n",
"print('The value of Td = %.2f kohm' %(Rd/1000))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The value of Td = 5.00 kohm\n"
]
}
],
"prompt_number": 4
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 10.8 Page No 403"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"#initialisation of variables\n",
"Id=3.0*10**-3\n",
"Vds=10.0\n",
"Vdd=25.0\n",
"Vgs=2.3\n",
"\n",
"#Calculations\n",
"Rs=Vgs/Id\n",
"Rd=((Vdd-Vds)/Id)-Rs\n",
"\n",
"#Results\n",
"print('The value of Rd = %.2f ohm' %(Rd/1000))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The value of Rd = 4.23 ohm\n"
]
}
],
"prompt_number": 5
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 10.9 Page No 405"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"#initialisation of variables\n",
"Id=3.0*10**-3\n",
"Vds=10.0\n",
"Vdd=25.0\n",
"Vg=5.2\n",
"Vgsoff=-6\n",
"Idss=8.0*10**-3\n",
"R2=1.0*10**6\n",
"\n",
"#Calculations\n",
"R=(Vdd-Vds)/Id#R=(Rs+Rd)/2\n",
"Rd=R/2\n",
"Rs=Rd\n",
"Vgs=Id*Rs\n",
"Vgs=Vgsoff*(1-math.sqrt(Id/Idss))\n",
"Vs=Id*Rs\n",
"Vg=Vs-(-Vgs)\n",
"R1=((Vdd-Vg)*R2)/Vg\n",
"\n",
"#Results\n",
"print('The value of R = %.2f Mohm' %(R1/10**6))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The value of R = 3.83 Mohm\n"
]
}
],
"prompt_number": 6
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 10.11, Page No 412"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"#initialisation of variables\n",
"\n",
"Vee=20.0\n",
"Id=3.0*10**-3\n",
"Vds=9.0\n",
"Vbe=.7\n",
"Vb=0\n",
"Ve=Vee-Vbe\n",
"\n",
"#Calculations\n",
"Re=Ve/Id\n",
"Re=6.8*10**3#satnadard value\n",
"Id=Ve/Re\n",
"Idss=16*10**-3\n",
"Vgsoff=-8\n",
"Vgs=Vgsoff*(1-math.sqrt(Id/Idss))\n",
"Vs=Vb-Vgs\n",
"Vrd=Vee-Vds-Vs\n",
"Rd=Vrd/Id\n",
"\n",
"#Results\n",
"print('The value of Rd = %.2f V' %(Rd/1000))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The value of Rd = 2.24 V\n"
]
}
],
"prompt_number": 7
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 10.12 Page No 415"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math \n",
"\n",
"#initialisation of variables\n",
"Idss=5.0*10**-3\n",
"Vgsoff=6.0\n",
"Rs=3.3*10**3\n",
"Vdd=20.0\n",
"Rd=Rs\n",
"\n",
"#Calculations\n",
"print(\"when Id=0 % Vgs=Vs=0\")\n",
"Id=0\n",
"Vgs=0\n",
"Vs=0\n",
"print(\" at point A universal transfer characteristic Id/Idss and Vgs/Vgsoff=0\")\n",
"Id=1.5*10**-3\n",
"Vgs=Id*Rs\n",
"y=Id/Idss\n",
"x=Vgs/Vgsoff\n",
"print(\" point B the universal transfer charecteristic x=.825 and y=.3\")\n",
"Id=.2*Idss\n",
"Vds=Vdd-Id*(Rd+Rs)\n",
"\n",
"#Results\n",
"print('The value of Vds = %.2f V' %(Vds))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"when Id=0 % Vgs=Vs=0\n",
" at point A universal transfer characteristic Id/Idss and Vgs/Vgsoff=0\n",
" point B the universal transfer charecteristic x=.825 and y=.3\n",
"The value of Vds = 13.40 V\n"
]
}
],
"prompt_number": 8
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 10.13 Page No 416"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"#initialisation of variables\n",
"\n",
"Idss=9.0*10**-3\n",
"Vgsoff=7.0\n",
"Vdd=22.0\n",
"R1=4.7*10**6\n",
"R2=1.0*10**6\n",
"Rs=2.7*10**3\n",
"Rd=Rs\n",
"\n",
"#Calculations\n",
"Vg=(Vdd*R2)/(R1+R2)\n",
"print(\"when Vgs=0 % Vgs/Vgsoff=0\")\n",
"Id=Vg/Rs\n",
"print(\"when Vgs/Vgsoff=.5\")\n",
"Vgs=.5*(-Vgsoff)\n",
"Id=(Vg-Vgs)/Rs\n",
"x=Id/Idss\n",
"print(\" point Y on universal characteristic x=.3 and Vgs/Vgsoff=.5\")\n",
"print(\"draw voltage divider bias line through X nad Y where bisa line intersect transfer curve\")\n",
"Id=.29*Idss\n",
"Vds=Vdd-Id*(Rd+Rs)\n",
"\n",
"#Results\n",
"print('The value of Vds= %.2f V' %(Vds))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"when Vgs=0 % Vgs/Vgsoff=0\n",
"when Vgs/Vgsoff=.5\n",
" point Y on universal characteristic x=.3 and Vgs/Vgsoff=.5\n",
"draw voltage divider bias line through X nad Y where bisa line intersect transfer curve\n",
"The value of Vds= 7.91 V\n"
]
}
],
"prompt_number": 9
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 10.14 Page No 419"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"#initialisation of variables\n",
"\n",
"Vdd=40.0\n",
"R2=1.0*10**6\n",
"R1=5.6*10**6\n",
"Rd=4.7\n",
"\n",
"#Calculations\n",
"Vg=(Vdd*R2)/(R1+R2)\n",
"print(\"from the point where the bias line intersect the transfer curve\")\n",
"Id=6.2\n",
"Vds=Vdd-Id*Rd\n",
"\n",
"#Results\n",
"print('The value of Vds= %.2f V' %(Vds))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"from the point where the bias line intersect the transfer curve\n",
"The value of Vds= 10.86 V\n"
]
}
],
"prompt_number": 10
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 10.16, Page No 422"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"#initialisation of variables\n",
"rDS=25.0\n",
"Vgsoff=10.0\n",
"Vds=200.0*10**-3\n",
"Vdd=12.0\n",
"\n",
"#Calculations\n",
"Id=Vds/rDS\n",
"Rd=Vdd/Id\n",
"Vi=-(Vgsoff+1)\n",
"\n",
"#Results\n",
"print('The value of Vi= %.2f V' %(Vi))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The value of Vi= -11.00 V\n"
]
}
],
"prompt_number": 11
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 10.17, Page No 424"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"#initialisation of variables\n",
"\n",
"Vdd=50.0\n",
"Rd=10.0\n",
"R2=1.0*10**6\n",
"rDS=0.25\n",
"\n",
"#Calculations\n",
"Id=Vdd/Rd\n",
"print(\" from transfer curve at Id=5 and Vgs=5.7\")\n",
"Vgs=5.7\n",
"R1=((Vdd-Vgs)*R2)/Vgs#use 6.8Mohm to make Vgs>5.7V to ensure that the FET is biased on\n",
"Vds=Id*rDS\n",
"\n",
"#Results\n",
"print('The value of Vds= %.2f V' %(Vds))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" from transfer curve at Id=5 and Vgs=5.7\n",
"The value of Vds= 1.25 V\n"
]
}
],
"prompt_number": 12
}
],
"metadata": {}
}
]
}