{ "metadata": { "name": "Chapter_8" }, "nbformat": 2, "worksheets": [ { "cells": [ { "cell_type": "markdown", "source": [ "

Chapter 8: FET Amplifiers

" ] }, { "cell_type": "markdown", "source": [ "

Example 8.1, Page Number: 253

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "", "# variable declaration", "g_m=4.0*10**-3; #gm value", "R_d=1.5*10**3; #resistance", "", "#calculation", "A_v=g_m*R_d; #voltage gain", "", "#result", "print \"Voltage gain = %.2f\" %A_v" ], "language": "python", "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Voltage gain = 6.00" ] } ], "prompt_number": 1 }, { "cell_type": "markdown", "source": [ "

Example 8.2, Page Number: 253

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "", "# variable declaration", "r_ds=10.0*10**3;", "R_d=1.5*10**3; #from previous question", "g_m=4.0*10**-3; #from previous question", "", "#calculation", "A_v=g_m*((R_d*r_ds)/(R_d+r_ds)); #voltage gain", "", "#result", "print \"Voltage gain = %.2f\" %A_v" ], "language": "python", "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Voltage gain = 5.22" ] } ], "prompt_number": 2 }, { "cell_type": "markdown", "source": [ "

Example 8.3, Page Number:254

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "", "# variable declaration", "R_s=560; #resistance in ohm", "R_d=1.5*10**3; #resistance in ohm", "g_m=4*10**-3; #g_m value", "", "#calculation", "A_v=(g_m*R_d)/(1+(g_m*R_s)) #voltage gain", "", "#result", "print \"Voltage gain = %.2f\" %A_v" ], "language": "python", "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Voltage gain = 1.85" ] } ], "prompt_number": 3 }, { "cell_type": "markdown", "source": [ "

Example 8.4, Page Number: 257

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "", "#Variable declaration", "vdd=12.0 #volts", "Id=1.96*10**-3 #Amp", "Rd=3.3*10**3 #ohm", "Idss=12.0*10**-3 #Amp", "Rs=910 # Ohm", "vgsoff= 3 #v", "vin=0.1 #V", "", "#calculation", "vd=vdd-(Id*Rd)", "vgs=-Id*Rs", "gm0=2*Idss/(abs(vgsoff))", "gm=0.00325 #mS", "vout=gm*Rd*vin", "vout=vout*2*1.414", "#Result", "print\"Total output ac voltage(peak-to-peak) = %f V \\nridig on DC value of %fV \"%(vout,vd)" ], "language": "python", "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Total output ac voltage(peak-to-peak) = 3.033030 V ", "ridig on DC value of 5.532000V " ] } ], "prompt_number": 4 }, { "cell_type": "markdown", "source": [ "

Example 8.5, Page Number: 258

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "", "# variable declaration", "R_D=3.3*10**3; #resistance in ohm", "R_L=4.7*10**3; #load resistance in ohm", "g_m=3.25*10**-3; #from previous question", "V_in=100.0*10**-3; #previous question", "", "#calculation", "R_d=(R_D*R_L)/(R_D+R_L); #Equivalent drain resistance", "V_out=g_m*R_d*V_in; #output RMS voltage in volt", "", "#result", "print \"Output voltage rms value = %.2f Volts\" %V_out" ], "language": "python", "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Output voltage rms value = 0.63 Volts" ] } ], "prompt_number": 5 }, { "cell_type": "markdown", "source": [ "

Example 8.6, Page Number: 259

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "", "# variable declaration", "I_GSS=30.0*10**-9; #current in ampere", "V_GS=10.0; #ground-source voltage", "R_G=10.0*10**6; #resistance in ohm", "", "#calculation", "R_IN_gate=V_GS/I_GSS; #gate input resistance", "R_in=(R_IN_gate*R_G)/(R_IN_gate+R_G); #parallel combination", "", "#result", "print \"Input resistance as seen by signal source = %.2f ohm\" %R_in" ], "language": "python", "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Input resistance as seen by signal source = 9708737.86 ohm" ] } ], "prompt_number": 6 }, { "cell_type": "markdown", "source": [ "

Example 8.7, Page Number: 260

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "", "# variable declaration", "I_DSS=200.0*10**-3;", "g_m=200.0*10**-3;", "V_in=500.0*10**-3;", "V_DD=15.0;", "R_D=33.0;", "R_L=8.2*10**3;", "", "#calculation", "I_D=I_DSS; #Amplifier is zero biased", "V_D=V_DD-I_D*R_D;", "R_d=(R_D*R_L)/(R_D+R_L);", "V_out=g_m*R_d*V_in;", "", "#result", "print \"DC output voltage = %.2f Volts\" %V_D", "print \"AC output voltage = %.2f volts\" %V_out" ], "language": "python", "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "DC output voltage = 8.40 Volts", "AC output voltage = 3.29 volts" ] } ], "prompt_number": 7 }, { "cell_type": "markdown", "source": [ "

Example 8.8, Page Number: 262

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "", "# Theoretical example", "# result", "", "print \"Part A:\\nQ point: V_GS=-2V I_D=2.5mA. At V_GS=-1V, I_D=3.4mA,\"", "print \"At V_GS=-3V, I_D=1.8mA. So peak to peak drain current is\" ", "print \"the difference of the two drain currents=1.6mA\"", "print \"\\nPart B:\\nQ point: V_GS=0V I_D=4mA. At V_GS=1V, I_D=5.3mA,\"", "print \"At V_GS=-1V, I_D=2.5mA. So peak to peak drain current is\"", "print\" the difference of the two drain currents=2.8mA\"", "print \"\\nPart C:\\nQ point: V_GS=8V I_D=2.5mA. At V_GS=9V, I_D=3.9mA,\"", "print \" At V_GS=7V, I_D=1.7mA. So peak to peak drain current is\"", "print \" the difference of the two drain currents=2.2mA\"" ], "language": "python", "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Part A:", "Q point: V_GS=-2V I_D=2.5mA. At V_GS=-1V, I_D=3.4mA,", "At V_GS=-3V, I_D=1.8mA. So peak to peak drain current is", "the difference of the two drain currents=1.6mA", "", "Part B:", "Q point: V_GS=0V I_D=4mA. At V_GS=1V, I_D=5.3mA,", "At V_GS=-1V, I_D=2.5mA. So peak to peak drain current is", " the difference of the two drain currents=2.8mA", "", "Part C:", "Q point: V_GS=8V I_D=2.5mA. At V_GS=9V, I_D=3.9mA,", " At V_GS=7V, I_D=1.7mA. So peak to peak drain current is", " the difference of the two drain currents=2.2mA" ] } ], "prompt_number": 8 }, { "cell_type": "markdown", "source": [ "

Example 8.9, Page Number:263

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "", "# variable declaration", "R_1=47.0*10**3;", "R_2=8.2*10**3;", "R_D=3.3*10**3;", "R_L=33.0*10**3;", "I_D_on=200.0*10**-3;", "V_GS=4.0;", "V_GS_th=2.0;", "g_m=23*10**-3;", "V_in=25*10**-3;", "V_DD=15.0;", "", "#calculation", "V_GSnew=(R_2/(R_1+R_2))*V_DD;", "K=I_D_on/((V_GS-V_GS_th)**2)", "#K=value_of_K(200*10**-3,4,2);", "K=K*1000;", "I_D=K*((V_GSnew-V_GS_th)**2);", "V_DS=V_DD-I_D*R_D/1000;", "R_d=(R_D*R_L)/(R_D+R_L);", "V_out=g_m*V_in*R_d;", "", "#result", "print \"Drain to source voltage = %.2f volts\" %V_GSnew", "print \"Drain current = %.2f mA\" %I_D", "print \"Gate to source voltage = %.2f volts\" %V_DS", "print \"AC output voltage = %.2f volts\" %V_out", "print \"Answer in textbook are approximated\"" ], "language": "python", "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Drain to source voltage = 2.23 volts", "Drain current = 2.61 mA", "Gate to source voltage = 6.40 volts", "AC output voltage = 1.72 volts", "Answer in textbook are approximated" ] } ], "prompt_number": 9 }, { "cell_type": "markdown", "source": [ "

Example 8.10, Page Number: 266

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "", "# variable declaration", "V_DD=-15.0; #p=channel MOSFET", "g_m=2000.0*10**-6; #minimum value from datasheets", "R_D=10.0*10**3;", "R_L=10.0*10**3;", "R_S=4.7*10**3;", "", "#calculation", "R_d=(R_D*R_L)/(R_D+R_L); #effective drain resistance", "A_v=g_m*R_d;", "R_in_source=1.0/g_m;", "#signal souce sees R_S in parallel with ip rest at source terminal(R_in_source)", "R_in=(R_in_source*R_S)/(R_in_source+R_S); ", "", "#result ", "print \"minimum voltage gain = %.2f\" %A_v", "print \"Input resistance seen from signal source = %.2f ohms\" %R_in" ], "language": "python", "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "minimum voltage gain = 10.00", "Input resistance seen from signal source = 451.92 ohms" ] } ], "prompt_number": 10 } ] } ] }