path: root/Electronic_Devices_/Chapter10.ipynb

{
 "metadata": {
  "name": "Chapter_10"
 }, 
 "nbformat": 2, 
 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "markdown", 
     "source": [
      "<h1>Chapter 10: Amplifier Frequency Response<h1>"
     ]
    }, 
    {
     "cell_type": "markdown", 
     "source": [
      "<h3>Example 10.1, Page Number: 311<h3>"
     ]
    }, 
    {
     "cell_type": "code", 
     "collapsed": false, 
     "input": [
      "'''Gain in decibel'''", 
      "", 
      "import math", 
      "#Pout/P in=250;", 
      "A_p=250.0", 
      "A_p_dB=10*math.log10(A_p)", 
      "print('Power gain(dB) when power gain is 250 = %d'% math.ceil(A_p_dB));", 
      "A_p=100.0", 
      "A_p_dB=10*math.log10(A_p)", 
      "print('Power gain(dB) when power gain is 100 = %d'%A_p_dB)", 
      "A_p=10.0", 
      "A_p_dB=20*math.log10(A_p)", 
      "print('Voltage gain(dB) when Voltage gain is 10 = %d'%A_p_dB)", 
      "A_p=0.50", 
      "A_p_dB=10*math.log10(A_p)", 
      "print('Power gain(dB) when voltage gain is 0.50 = %d'%A_p_dB)", 
      "A_p=0.707", 
      "A_p_dB=20*math.log10(A_p)", 
      "print('Power gain(dB) when power gain is 0.707 = %d'%A_p_dB)"
     ], 
     "language": "python", 
     "outputs": [
      {
       "output_type": "stream", 
       "stream": "stdout", 
       "text": [
        "Power gain(dB) when power gain is 250 = 24", 
        "Power gain(dB) when power gain is 100 = 20", 
        "Voltage gain(dB) when Voltage gain is 10 = 20", 
        "Power gain(dB) when voltage gain is 0.50 = -3", 
        "Power gain(dB) when power gain is 0.707 = -3"
       ]
      }
     ], 
     "prompt_number": 19
    }, 
    {
     "cell_type": "markdown", 
     "source": [
      "<h3>Example 10.2, Page Number: 313<h3>"
     ]
    }, 
    {
     "cell_type": "code", 
     "collapsed": false, 
     "input": [
      "'''Gain in decibel'''", 
      "", 
      "", 
      "#input voltage=10V", 
      "#at -3dB voltage gain from table is 0.707", 
      "v_out=0.707*10;", 
      "print('output voltage in volts at -3dB gain  = %.2f'%v_out)", 
      "#at -6dB voltage gain from table is 0.5", 
      "v_out=0.5*10;", 
      "print('output voltage in volts at -6dB gain = %d'%v_out)", 
      "#at -12dB voltage gain from table is 0.25", 
      "v_out=0.25*10;", 
      "print('output voltage in volts at -12dB gain = %.1f'%v_out)", 
      "#at -24dB voltage gain from table is 0.0625", 
      "v_out=0.0625*10;", 
      "print('output voltage in volts at -24dB gain = %.3f'%v_out)"
     ], 
     "language": "python", 
     "outputs": [
      {
       "output_type": "stream", 
       "stream": "stdout", 
       "text": [
        "output voltage in volts at -3dB gain  = 7.07", 
        "output voltage in volts at -6dB gain = 5", 
        "output voltage in volts at -12dB gain = 2.5", 
        "output voltage in volts at -24dB gain = 0.625"
       ]
      }
     ], 
     "prompt_number": 20
    }, 
    {
     "cell_type": "markdown", 
     "source": [
      "<h3>Example 10.3, Page Number: 316<h3>"
     ]
    }, 
    {
     "cell_type": "code", 
     "collapsed": false, 
     "input": [
      "'''Lower critical frequency'''", 
      "", 
      "import math", 
      "R_in=1.0*10**3;", 
      "C1=1.0*10**-6;", 
      "A_v_mid=100.0;    #mid range voltage gain", 
      "f_c=1/(2*math.pi*R_in*C1);", 
      "#at f_c, capacitive reactance is equal to resistance(X_C1=R_in)", 
      "attenuation=0.707;", 
      "#A_v is gain at lower critical frequency", 
      "A_v=0.707*A_v_mid;", 
      "print('lower critical frequency = %f Hz'%f_c)", 
      "print('attenuation at lower critical frequency =%.3f'%attenuation)", 
      "print('gain at lower critical frequency = %.1f'%A_v)"
     ], 
     "language": "python", 
     "outputs": [
      {
       "output_type": "stream", 
       "stream": "stdout", 
       "text": [
        "lower critical frequency = 159.154943 Hz", 
        "attenuation at lower critical frequency =0.707", 
        "gain at lower critical frequency = 70.7"
       ]
      }
     ], 
     "prompt_number": 21
    }, 
    {
     "cell_type": "markdown", 
     "source": [
      "<h3>Example 10.4, Page Number: 317<h3>"
     ]
    }, 
    {
     "cell_type": "code", 
     "collapsed": false, 
     "input": [
      "'''Voltage gains'''", 
      "", 
      "A_v_mid=100.0;", 
      "#At 1Hz frequency,voltage gain is 3 dB less than at midrange. At -3dB, the voltage is reduced by a factor of 0.707", 
      "A_v=0.707*A_v_mid;", 
      "print('actual voltage gain at 1Hz frequency = %.1f'%A_v)", 
      "#At 100Hz frequency,voltage gain is 20 dB less than at critical frequency (f_c ). At -20dB, the voltage is reduced by a factor of 0.1", 
      "A_v=0.1*A_v_mid;", 
      "print('actual voltage gain at 100Hz frequency = %d'%A_v)", 
      "#At 10Hz frequency,voltage gain is 40 dB less than at critical frequency (f_c). At -40dB, the voltage is reduced by a factor of 0.01", 
      "A_v=0.01*A_v_mid;", 
      "print('actual voltage gain at 10Hz frequency = %d'%A_v)"
     ], 
     "language": "python", 
     "outputs": [
      {
       "output_type": "stream", 
       "stream": "stdout", 
       "text": [
        "actual voltage gain at 1Hz frequency = 70.7", 
        "actual voltage gain at 100Hz frequency = 10", 
        "actual voltage gain at 10Hz frequency = 1"
       ]
      }
     ], 
     "prompt_number": 22
    }, 
    {
     "cell_type": "markdown", 
     "source": [
      "<h3>Example 10.5, Page Number: 319<h3>"
     ]
    }, 
    {
     "cell_type": "code", 
     "collapsed": false, 
     "input": [
      "'''Output RC circuit'''", 
      "", 
      "import math", 
      "R_C=10.0*10**3;", 
      "C3=0.1*10**-6;", 
      "R_L=10*10**3;", 
      "A_v_mid=50;", 
      "f_c=1/(2*math.pi*(R_L+R_C)*C3);", 
      "print('lower critical frequency = %f Hz'%f_c)", 
      "#at midrange capacitive reactance is zero", 
      "X_C3=0;", 
      "attenuation=R_L/(R_L+R_C);    ", 
      "print('attenuation at midrange frequency = %.1f'%attenuation)", 
      "#at critical frequency, capacitive reactance equals total resistance", 
      "X_C3=R_L+R_C;", 
      "attenuation=R_L/(math.sqrt((R_C+R_L)**2+X_C3**2));", 
      "print('attenuation at critical frequency = %f'%attenuation)", 
      "A_v=0.707*A_v_mid;", 
      "print('gain at critical frequency = %.2f'%A_v)"
     ], 
     "language": "python", 
     "outputs": [
      {
       "output_type": "stream", 
       "stream": "stdout", 
       "text": [
        "lower critical frequency = 79.577472 Hz", 
        "attenuation at midrange frequency = 0.5", 
        "attenuation at critical frequency = 0.353553", 
        "gain at critical frequency = 35.35"
       ]
      }
     ], 
     "prompt_number": 23
    }, 
    {
     "cell_type": "markdown", 
     "source": [
      "<h3>Example 10.6, Page Number: 321<h3>"
     ]
    }, 
    {
     "cell_type": "code", 
     "collapsed": false, 
     "input": [
      "'''Bypass RC circuit BJT'''", 
      "", 
      "import math", 
      "B_ac=100.0;", 
      "r_e=12.0;", 
      "R1=62.0*10**3;", 
      "R2=22.0*10**3;", 
      "R_S=1.0*10**3;", 
      "R_E=1.0*10**3;", 
      "C2=100.0*10**-6;", 
      "#Base circuit impedance= parallel combination of R1, R2, R_S", 
      "R_th=(R1*R2*R_S)/(R1*R2+R2*R_S+R_S*R1);", 
      "#Resistance looking at emitter", 
      "R_in_emitter=r_e+(R_th/B_ac);", 
      "#resistance of equivalent bypass RC is parallel combination of R_E,R_in_emitter", 
      "R=(R_in_emitter*R_E)/(R_E+R_in_emitter);", 
      "f_c=1/(2*math.pi*R*C2);", 
      "print('critical frequency of bypass RC circuit = %f Hz'%f_c)"
     ], 
     "language": "python", 
     "outputs": [
      {
       "output_type": "stream", 
       "stream": "stdout", 
       "text": [
        "critical frequency of bypass RC circuit = 75.893960 Hz"
       ]
      }
     ], 
     "prompt_number": 24
    }, 
    {
     "cell_type": "markdown", 
     "source": [
      "<h3>Example 10.7, Page Number:323<h3>"
     ]
    }, 
    {
     "cell_type": "code", 
     "collapsed": false, 
     "input": [
      "'''input RC circuit FET'''", 
      "", 
      "import math", 
      "V_GS=-10.0;", 
      "I_GSS=25.0*10**-9;", 
      "R_G=10.0*10**6;", 
      "C1=0.001*10**-6;", 
      "R_in_gate=abs((V_GS/I_GSS));", 
      "R_in=(R_in_gate*R_G)/(R_G+R_in_gate);", 
      "f_c=1/(2*math.pi*R_in*C1);", 
      "print('critical frequency = %f Hz'%f_c)"
     ], 
     "language": "python", 
     "outputs": [
      {
       "output_type": "stream", 
       "stream": "stdout", 
       "text": [
        "critical frequency = 16.313382 Hz"
       ]
      }
     ], 
     "prompt_number": 25
    }, 
    {
     "cell_type": "markdown", 
     "source": [
      "<h3>Example 10.8, Page Number: 324<h3>"
     ]
    }, 
    {
     "cell_type": "code", 
     "collapsed": false, 
     "input": [
      "'''Low frequency response FET'''", 
      "", 
      "import math", 
      "V_GS=-12.0;", 
      "I_GSS=100.0*10**-9;", 
      "R_G=10.0*10**6;", 
      "R_D=10.0*10**3;", 
      "C1=0.001*10**-6;", 
      "C2=0.001*10**-6;", 
      "R_in_gate=abs((V_GS/I_GSS));", 
      "R_in=(R_in_gate*R_G)/(R_G+R_in_gate);", 
      "R_L=R_in;    #according to question", 
      "f_c_input=1/(2*math.pi*R_in*C1);", 
      "print('critical frequency of input RC circuit = %f Hz'%f_c_input)", 
      "f_c_output=1/(2*math.pi*(R_D+R_L)*C2)", 
      "print('critical frequency of output RC circuit = %f Hz'%f_c_output)"
     ], 
     "language": "python", 
     "outputs": [
      {
       "output_type": "stream", 
       "stream": "stdout", 
       "text": [
        "critical frequency of input RC circuit = 17.241786 Hz", 
        "critical frequency of output RC circuit = 17.223127 Hz"
       ]
      }
     ], 
     "prompt_number": 26
    }, 
    {
     "cell_type": "markdown", 
     "source": [
      "<h3>Example 10.9, Page Number: 327<h3>"
     ]
    }, 
    {
     "cell_type": "code", 
     "collapsed": false, 
     "input": [
      "'''Low frequency response BJT'''", 
      "", 
      "import math", 
      "B_ac=100.0;", 
      "r_e=16.0;", 
      "R1=62.0*10**3;", 
      "R2=22.0*10**3;", 
      "R_S=600.0;", 
      "R_E=1.0*10**3;", 
      "R_C=2.2*10**3;", 
      "R_L=10.0*10**3;", 
      "C1=0.1*10**-6;", 
      "C2=10.0*10**-6;", 
      "C3=0.1*10**-6;", 
      "#input RC circuit", 
      "R_in=(B_ac*r_e*R1*R2)/(B_ac*r_e*R1+B_ac*r_e*R2+R1*R2);", 
      "f_c_input=1/(2*math.pi*(R_S+R_in)*C1);", 
      "print('input frequency = %f Hz'%f_c_input)", 
      "#For bypass circuit; Base circuit impedance= parallel combination of R1, R2, R_S", 
      "R_th=(R1*R2*R_S)/(R1*R2+R2*R_S+R_S*R1);", 
      "#Resistance looking at emitter", 
      "R_in_emitter=r_e+(R_th/B_ac);", 
      "#resistance of equivalent bypass RC is parallel combination of R_E,R_in_emitter", 
      "R=(R_in_emitter*R_E)/(R_E+R_in_emitter);", 
      "f_c_bypass=1/(2*math.pi*R*C2);", 
      "print('critical frequency of bypass RC circuit = %f Hz'%f_c_bypass)", 
      "f_c_output=1/(2*math.pi*(R_C+R_L)*C3)", 
      "print('output frequency circuit = %f Hz'%f_c_output)", 
      "R_c=R_C*R_L/(R_C+R_L);", 
      "A_v_mid=R_c/r_e;", 
      "attenuation=R_in/(R_in+R_S);", 
      "A_v=attenuation*A_v_mid;    #overall voltage gain", 
      "A_v_mid_dB=20*math.log10(A_v);    ", 
      "print('overall voltage gain in dB = %f'%A_v_mid_dB)"
     ], 
     "language": "python", 
     "outputs": [
      {
       "output_type": "stream", 
       "stream": "stdout", 
       "text": [
        "input frequency = 773.916632 Hz", 
        "critical frequency of bypass RC circuit = 746.446517 Hz", 
        "output frequency circuit = 130.454871 Hz", 
        "overall voltage gain in dB = 38.042470"
       ]
      }
     ], 
     "prompt_number": 27
    }, 
    {
     "cell_type": "markdown", 
     "source": [
      "<h3>Example 10.10, Page Number: 330<h3>"
     ]
    }, 
    {
     "cell_type": "code", 
     "collapsed": false, 
     "input": [
      "'''input RC circuit BJT'''", 
      "", 
      "import math", 
      "B_ac=125.0;", 
      "C_be=20.0*10**-12;", 
      "C_bc=2.4*10**-12;", 
      "R1=22.0*10**3;", 
      "R2=4.7*10**3;", 
      "R_E=470.0;", 
      "R_S=600.0;", 
      "R_L=2.2*10**3;", 
      "V_CC=10.0;", 
      "V_B=(R2/(R1+R2))*V_CC;", 
      "V_E=V_B-0.7;", 
      "I_E=V_E/R_E;", 
      "r_e=25.0*10**-3/I_E;", 
      "#total resistance of input circuit is parallel combination of R1,R2,R_s,B_ac*r_e", 
      "R_in_tot=B_ac*r_e*R1*R2*R_S/(B_ac*r_e*R1*R2+B_ac*r_e*R1*R_S+B_ac*r_e*R2*R_S+R1*R2*R_S);", 
      "R_c= 1100.0#R_C*R_L/(R_C+R_L)", 
      "A_v_mid=R_c/r_e;", 
      "C_in_Miller=C_bc*(A_v_mid+1)", 
      "C_in_tot=C_in_Miller+C_be;", 
      "C_in_tot=C_in_tot*10**10", 
      "f_c=1/(2*math.pi*R_in_tot*C_in_tot);", 
      "print('total resistance of circuit = %f Ohm'%R_in_tot)", 
      "print('total capacitance = %f * 10^-10 F'%C_in_tot)", 
      "print('critical frequency = %f Hz'%f_c)"
     ], 
     "language": "python", 
     "outputs": [
      {
       "output_type": "stream", 
       "stream": "stdout", 
       "text": [
        "total resistance of circuit = 377.815676 Ohm", 
        "total capacitance = 2.606290 * 10^-10 F", 
        "critical frequency = 0.000162 Hz"
       ]
      }
     ], 
     "prompt_number": 28
    }, 
    {
     "cell_type": "markdown", 
     "source": [
      "<h3>Example 10.11, Page Number: 333<h3>"
     ]
    }, 
    {
     "cell_type": "code", 
     "collapsed": false, 
     "input": [
      "'''Critical frequency BJT output'''", 
      "", 
      "import math", 
      "C_bc=2.4*10**-12;    #from previous question", 
      "A_v=99.0;    #from previous question", 
      "R_C=2.2*10**3;", 
      "R_L=2.2*10**3;", 
      "R_c=R_C*R_L/(R_C+R_L);", 
      "C_out_Miller=C_bc*(A_v+1)/A_v;", 
      "f_c=1/(2*math.pi*R_c*C_bc);    #C_bc is almost equal to C_in_Miller", 
      "C_out_Miller=C_out_Miller*10**12", 
      "print('equivalent resistance = %d Ohm'%R_c)", 
      "print('equivalent capacitance =%f *10^-12 F'%C_out_Miller)", 
      "print('critical frequency =%f Hz'%f_c)"
     ], 
     "language": "python", 
     "outputs": [
      {
       "output_type": "stream", 
       "stream": "stdout", 
       "text": [
        "equivalent resistance = 1100 Ohm", 
        "equivalent capacitance =2.424242 *10^-12 F", 
        "critical frequency =60285963.292385 Hz"
       ]
      }
     ], 
     "prompt_number": 29
    }, 
    {
     "cell_type": "markdown", 
     "source": [
      "<h3>Example 10.12, Page Number: 334<h3>"
     ]
    }, 
    {
     "cell_type": "code", 
     "collapsed": false, 
     "input": [
      "'''FET capacitors'''", 
      "", 
      "C_iss=6.0*10**-12;", 
      "C_rss=2.0*10**-12;", 
      "C_gd=C_rss;", 
      "C_gs=C_iss-C_rss;", 
      "C_gd=C_gd*10**12", 
      "C_gs=C_gs*10**12", 
      "print('gate to drain capacitance = %.1f * 10^-12 F'%C_gd)", 
      "print('gate to source capacitance = %.1f * 10^-12 F'%C_gs)"
     ], 
     "language": "python", 
     "outputs": [
      {
       "output_type": "stream", 
       "stream": "stdout", 
       "text": [
        "gate to drain capacitance = 2.0 * 10^-12 F", 
        "gate to source capacitance = 4.0 * 10^-12 F"
       ]
      }
     ], 
     "prompt_number": 30
    }, 
    {
     "cell_type": "markdown", 
     "source": [
      "<h3>Example 10.13, Page Number:335 <h3>"
     ]
    }, 
    {
     "cell_type": "code", 
     "collapsed": false, 
     "input": [
      "'''Critical frequency FET input'''", 
      "", 
      "import math", 
      "C_iss=8.0*10**-12;", 
      "C_rss=3.0*10**-12;", 
      "g_m=6500.0*10**-6;    #in Siemens", 
      "R_D=1.0*10**3;", 
      "R_L=10.0*10**6;", 
      "R_s=50.0;", 
      "C_gd=C_rss;", 
      "C_gs=C_iss-C_rss;", 
      "R_d=R_D*R_L/(R_D+R_L);", 
      "A_v=g_m*R_d;", 
      "C_in_Miller=C_gd*(A_v+1);", 
      "C_in_tot=C_in_Miller+C_gs;", 
      "f_c=1/(2*math.pi*C_in_tot*R_s);", 
      "print('critical frequency of input RC circuit =%.3f *10^8 Hz'%(f_c*10**-8))"
     ], 
     "language": "python", 
     "outputs": [
      {
       "output_type": "stream", 
       "stream": "stdout", 
       "text": [
        "critical frequency of input RC circuit =1.158 *10^8 Hz"
       ]
      }
     ], 
     "prompt_number": 31
    }, 
    {
     "cell_type": "markdown", 
     "source": [
      "<h3>Example 10.14, Page Number: 336<h3>"
     ]
    }, 
    {
     "cell_type": "code", 
     "collapsed": false, 
     "input": [
      "'''Critical frequency FET input'''", 
      "", 
      "import math", 
      "C_gd=3.0*10**-12;    #from previous question", 
      "A_v=6.5;             #from previous question", 
      "R_d=1.0*10**3;       #from previous question", 
      "C_out_Miller=C_gd*(A_v+1)/A_v;", 
      "f_c=1/(2*math.pi*R_d*C_out_Miller);", 
      "print('critical frequency of the output circuit = %d Hz'%f_c)"
     ], 
     "language": "python", 
     "outputs": [
      {
       "output_type": "stream", 
       "stream": "stdout", 
       "text": [
        "critical frequency of the output circuit = 45978094 Hz"
       ]
      }
     ], 
     "prompt_number": 32
    }, 
    {
     "cell_type": "markdown", 
     "source": [
      "<h3>Example 10.15, Page Number: 339<h3>"
     ]
    }, 
    {
     "cell_type": "code", 
     "collapsed": false, 
     "input": [
      "'''Bandwidth'''", 
      "", 
      "f_cu=2000.0;", 
      "f_cl=200.0;", 
      "BW=f_cu-f_cl;", 
      "print('bandwidth = %d Hz'%BW)"
     ], 
     "language": "python", 
     "outputs": [
      {
       "output_type": "stream", 
       "stream": "stdout", 
       "text": [
        "bandwidth = 1800 Hz"
       ]
      }
     ], 
     "prompt_number": 33
    }, 
    {
     "cell_type": "markdown", 
     "source": [
      "<h3>Example 10.16, Page Number: 340<h3>"
     ]
    }, 
    {
     "cell_type": "code", 
     "collapsed": false, 
     "input": [
      "'''Bandwidth transistor'''", 
      "", 
      "f_T=175.0*10**6;    #in hertz", 
      "A_v_mid=50.0;", 
      "BW=f_T/A_v_mid;", 
      "print('bandwidth = %d Hz'%BW)"
     ], 
     "language": "python", 
     "outputs": [
      {
       "output_type": "stream", 
       "stream": "stdout", 
       "text": [
        "bandwidth = 3500000 Hz"
       ]
      }
     ], 
     "prompt_number": 34
    }, 
    {
     "cell_type": "markdown", 
     "source": [
      "<h3>Example 10.17, Page Number: 341<h3>"
     ]
    }, 
    {
     "cell_type": "code", 
     "collapsed": false, 
     "input": [
      "'''Bandwidth 2stage amplifier'''", 
      "", 
      "f_cl=1.0*10**3;    #lower critical frequency of 2nd stage in hertz", 
      "f_cu=100.0*10**3;  #upper critical frequency of 1st stage in hertz", 
      "BW=f_cu-f_cl;", 
      "print('bandwidth = %d Hz'%BW)"
     ], 
     "language": "python", 
     "outputs": [
      {
       "output_type": "stream", 
       "stream": "stdout", 
       "text": [
        "bandwidth = 99000 Hz"
       ]
      }
     ], 
     "prompt_number": 35
    }, 
    {
     "cell_type": "markdown", 
     "source": [
      "<h3>Example 10.18, Page Number: 341<h3>"
     ]
    }, 
    {
     "cell_type": "code", 
     "collapsed": false, 
     "input": [
      "'''Bandwidth 2stage amplifier'''", 
      "", 
      "import math", 
      "n=2.0;    #n is the number of stages of amplifier", 
      "f_cl=500.0;", 
      "f_cu=80.0*10**3;", 
      "f_cl_new=f_cl/(math.sqrt(2**(1/n)-1));", 
      "f_cu_new=f_cu*(math.sqrt(2**(1/n)-1));", 
      "BW=f_cu_new-f_cl_new;", 
      "print('bandwidth = %f Hz'%BW)"
     ], 
     "language": "python", 
     "outputs": [
      {
       "output_type": "stream", 
       "stream": "stdout", 
       "text": [
        "bandwidth = 50710.653245 Hz"
       ]
      }
     ], 
     "prompt_number": 36
    }
   ]
  }
 ]
}