{ "metadata": { "name": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 14: Solid State Electronics" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 14.1, Page 718" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Variable declaration\n", "e = 1.6e-019; # Charge on an electron, C\n", "mu_h = 0.048; # Mobility of holes, metre square/volt-s\n", "mu_e = 0.135; # Mobility of electrons, metre square/volt-s \n", "\n", "#Calculations\n", "# For P-type semiconductor\n", "rho_p = 1e-01; # Resistivity of P type silicon, omh-m\n", "# As rho_p = 1/(e*N_a*mu_h), solving for N_a\n", "N_a = 1/(e*rho_p*mu_h); # Density of acceptor atoms, per metre cube\n", "# For N-type semiconductor\n", "rho_n = 1e-01; # Resistivity of N type silicon, omh-m\n", "# As rho_n = 1/(e*N_d*mu_h), solving for N_d\n", "N_d = 1/(e*rho_n*mu_e); # Density of donor atoms, per metre cube\n", "\n", "#Results\n", "print \"Density of acceptor atoms = %4.2e per metre cube\"%N_a\n", "print \"Density of donor atoms = %4.2e per metre cube\"%N_d #incorrect answer in textbook\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Density of acceptor atoms = 1.30e+21 per metre cube\n", "Density of donor atoms = 4.63e+20 per metre cube\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 14.2, Page 718" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Variable declaration\n", "e = 1.6e-019; # Charge on an electron, C\n", "mu_e = 0.36; # Mobility of an electron, metre square/V-s\n", "mu_h = 0.17; # Mobility of a hole, metre square/V-s\n", "n_i = 2.5e+018; # Intrinsic concentration of Ge sample, per metre cube\n", "\n", "#Calculations\n", "sigma = e*n_i*(mu_h+mu_e); # Electrical conductivity of Ge sample, mho per metre\n", "rho = 1/sigma; # Electrical resistivity of Ge, ohm-m\n", "\n", "#Results\n", "print \"The electrical conductivity of intrinsic germanium sample = %5.3f mho/m\"%sigma\n", "print \"The electrical resistivity of intrinsic germanium sample = %3.1f ohm-m\"%rho\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The electrical conductivity of intrinsic germanium sample = 0.212 mho/m\n", "The electrical resistivity of intrinsic germanium sample = 4.7 ohm-m\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 14.3, Page 719" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Variable declaration\n", "e = 1.6e-019; # Charge on an electron, C\n", "mu_e = 0.13; # Mobility of an electron, metre square/V-s\n", "mu_h = 0.05; # Mobility of a hole, metre square/V-s\n", "n_i = 1.5e+016; # Intrinsic concentration of Si, per metre cube\n", "\n", "#Calculations\n", "# Pure Si\n", "sigma = e*n_i*(mu_h+mu_e); # Electrical conductivity of Si, mho per metre\n", "# Pure Si doped with donor impurity\n", "n_e = 5e+028/1e+09; # Concentration of electrons, per metre cube\n", "sigma_n = e*n_e*mu_e; # Electrical conductivity of Si doped with donor impurity, mho per metre\n", "# Pure Si doped with acceptor impurity\n", "n_h = 5e+028/1e+09; # Concentration of holes, per metre cube\n", "sigma_p = e*n_h*mu_h; # Electrical conductivity of Si doped with acceptor impurity, mho per metre\n", "\n", "#Results\n", "print \"The electrical conductivity of pure Si = %4.2e mho/m\"%sigma\n", "print \"The electrical conductivity of Si doped with donor impurity = %4.2f mho/m\"%sigma_n\n", "print \"The electrical conductivity of Si doped with acceptor impurity= %4.2f mho/m\"%sigma_p\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The electrical conductivity of pure Si = 4.32e-04 mho/m\n", "The electrical conductivity of Si doped with donor impurity = 1.04 mho/m\n", "The electrical conductivity of Si doped with acceptor impurity= 0.40 mho/m\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 14.4, Page 720" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import *\n", "\n", "#Variable declaration\n", "Nd = 1; # For simplicity assume donor concentration to be unity, per metre cube\n", "Nd_prime = 3*Nd; # Thrice the donor concentration, per metre cube\n", "dE_CF1 = 0.5; # Energy difference between normal Fermi level and conduction level, eV\n", "k_BT = 0.03; # Thermal energy at room temperature, eV\n", "\n", "#Calculations\n", "# As Nd_prime/Nd = exp((dE_CF1 - dE_CF2))/k_BT, solving for dE_CF2\n", "dE_CF2 = dE_CF1-k_BT*log(Nd_prime/Nd); # Energy difference between new postion of Fermi level and conduction level, eV\n", "\n", "#Result\n", "print \"The new postion of Fermi level when donor concentration is trebled = %5.3f eV\"%dE_CF2\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The new postion of Fermi level when donor concentration is trebled = 0.467 eV\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 14.5, Page 721" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import *\n", "\n", "#Variable declaration\n", "e = 1.6e-019; # Charge on an electron, C\n", "T = 300; # Room temperature, K\n", "J0 = 300e-03; # Saturation current density of the pn junction diode, A/metre square\n", "J = 1e+05; # Forward current density of pn junction diode, A/metre square\n", "k_B = 1.38e-023; # Boltzmann constant, J/K\n", "eta = 1; # Ideality factor for Ge diode\n", "\n", "#Calculations\n", "# As J = J0*exp(e*V/(eta*k_B*T)), solving for V\n", "V = eta*k_B*T/e*log(J/J0); # Voltage required to cause a forward current density in pn junction diode, volt\n", "\n", "#Results\n", "print \"The voltage required to cause a forward current density in pn junction diode = %5.3f V\"%V\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The voltage required to cause a forward current density in pn junction diode = 0.329 V\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 14.6, Page 721" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import *\n", "\n", "#Variable declaration\n", "e = 1.6e-019; # Charge on an electron, C\n", "T = 300; # Room temperature, K\n", "J0 = 200e-03; # Saturation current density of the pn junction diode, A/metre square\n", "J = 5e+04; # Forward current density of pn junction diode, A/metre square\n", "k_B = 1.38e-023; # Boltzmann constant, J/K\n", "eta = 1; # Ideality factor for Ge diode\n", "\n", "#Calculations\n", "# As J = J0*exp(e*V/(eta*k_B*T)), solving for V\n", "V = eta*k_B*T/e*log(J/J0); # Voltage required to cause a forward current density in pn junction diode, volt\n", "\n", "#Result\n", "print \"The voltage required to cause a forward current density in pn junction diode = %5.3f V\"%V\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The voltage required to cause a forward current density in pn junction diode = 0.322 V\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 14.7, Page 722" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import *\n", "\n", "#Variable declaration\n", "e = 1.6e-019; # Charge on an electron, C\n", "T = 300; # Room temperature, K\n", "J0 = 300e-03; # Saturation current density of the pn junction diode, A/metre square\n", "J = 1e+05; # Forward current density of pn junction diode, A/metre square\n", "k_B = 1.38e-023; # Boltzmann constant, J/K\n", "eta = 2; # Ideality factor for Ge diode\n", "\n", "#Calculations\n", "# As J = J0*exp(e*V/(eta*k_B*T)), solving for V\n", "V = eta*k_B*T/e*log(J/J0); # Voltage required to cause a forward current density in pn junction diode, volt\n", "\n", "#Result\n", "print \"The voltage required to cause a forward current density in Si iode = %5.3f V\"%V\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The voltage required to cause a forward current density in Si iode = 0.658 V\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 14.8, Page 723" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Variable declaration\n", "I = 55e-03; # Forward current through Si diode, A\n", "V = 3; # Forward bias across Si diode, V\n", "eta = 2; # Ideality factor for Si diode\n", "\n", "#Calculations\n", "R_dc = V/I; # Static diode resistance, ohm\n", "R_ac = 0.026*eta/I; # Dynamic diode resistance, ohm\n", "\n", "#Results\n", "print \"The static diode resistance = %4.1f ohm\"%R_dc\n", "print \"The dynamic diode resistance = %5.3f ohm\"%R_ac\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The static diode resistance = 54.5 ohm\n", "The dynamic diode resistance = 0.945 ohm\n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 14.9, Page 723" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import *\n", "\n", "#Variable declaration\n", "R_L = 1000; # Load resistance across HWR, ohm\n", "V_rms = 200; # Rms value of voltage supply, V\n", "\n", "#Calculations\n", "V0 = sqrt(2)*V_rms; # Peak value of voltage, V\n", "I0 = V0/(R_L*1e-03); # Peak value of current, mA\n", "I_dc = I0/pi; # Average value of current, mA\n", "I_rms = I0/2; # Rms value of current, mA\n", "V_dc = I_dc*R_L/1e+03; # Dc output voltage, V\n", "PIV = V0; # Peak inverse voltage, V\n", "\n", "#Results\n", "print \"The average value of current = %2d mA\"%I_dc\n", "print \"The rms value of current = %5.1f mA\"%I_rms\n", "print \"The dc output voltage = %2d V\"%(V_dc/1)\n", "print \"PIV = %5.1f V\"%PIV\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The average value of current = 90 mA\n", "The rms value of current = 141.4 mA\n", "The dc output voltage = 90 V\n", "PIV = 282.8 V\n" ] } ], "prompt_number": 10 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 14.10, Page 724" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import *\n", "\n", "#Variable declaration\n", "R_L = 980; # Load resistance across FWR, ohm\n", "R_F = 20.; # Internal resistance of two crystal diodes in FWR, ohm\n", "V_rms = 50; # Rms value of voltage supply, V\n", "\n", "#Calculations\n", "V0 = sqrt(2)*V_rms; # Peak value of voltage, V\n", "I0 = V0/((R_L+R_F)*1e-03); # Peak value of current, mA\n", "I_dc = 2*I0/pi; # Average value of current, mA\n", "I_rms = I0/sqrt(2); # Rms value of current, mA\n", "V_dc = I_dc*R_L/1e+03; # Dc output voltage, V\n", "eta = 81.2/(1+R_F/R_L); # Rectification efficiency\n", "PIV = 2*V0; # Peak inverse voltage, V\n", "\n", "#Results\n", "print \"The average value of current = %2d mA\"%I_dc\n", "print \"The rms value of current = %2d mA\"%I_rms\n", "print \"The dc output voltage = %4.1f V\"%(V_dc/1)\n", "print \"The rectification efficiency = %4.1f percent\"%eta\n", "print \"PIV = %5.1f V\"%PIV\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The average value of current = 45 mA\n", "The rms value of current = 50 mA\n", "The dc output voltage = 44.1 V\n", "The rectification efficiency = 79.6 percent\n", "PIV = 141.4 V\n" ] } ], "prompt_number": 17 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 14.11, Page 725" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Variable declaration\n", "delta_IC = 1e-03; # Change in collector current, A\n", "delta_IB = 50e-06; # Change in base current, A\n", "\n", "#Calculations\n", "bta = delta_IC/delta_IB; # Base current amplification factor\n", "alpha = bta/(1+bta); # Emitter current amplification factor\n", "\n", "#Results\n", "print \"Alpha of BJT = %4.2f\"%alpha\n", "print \"Beta of BJT = %2d\"%bta\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Alpha of BJT = 0.95\n", "Beta of BJT = 20\n" ] } ], "prompt_number": 12 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 14.12, Page 725" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Variable declaration\n", "I_E = 2; # Emitter current, mA\n", "alpha = 0.88; # Emitter current amplification factor\n", "\n", "#Calculations\n", "I_C = alpha*I_E; # Collector current, mA\n", "I_B = I_E - I_C; # Base current of BJT in CB mode, mA\n", "\n", "#Result\n", "print \"The base current of BJT in CB mode = %4.2f mA\"%I_B\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The base current of BJT in CB mode = 0.24 mA\n" ] } ], "prompt_number": 13 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 14.13, Page 725" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Variable declaration\n", "I_CBO = 12.5e-03; # Reverse saturation current, mA\n", "I_E = 2; # Emitter current, mA\n", "I_C = 1.97; # Collector current, mA\n", "\n", "#Calculations\n", "# As I_C = alpha*I_E+I_CBO, solving for alpha\n", "alpha = (I_C - I_CBO)/I_E; # Emitter current gain\n", "I_B = I_E - I_C; # Base current, mA\n", "\n", "#Results\n", "print \"The emitter current gain = %5.3f\"%alpha\n", "print \"The base current = %4.2f mA\"%I_B\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The emitter current gain = 0.979\n", "The base current = 0.03 mA\n" ] } ], "prompt_number": 14 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 14.14, Page 726" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Variable declaration\n", "alpha = 0.98; # Emitter current amplification factor\n", "I_CBO = 5e-06; # Reverse saturation current, A\n", "\n", "#Calculations\n", "bta = alpha/(1-alpha); # Emitter current amplification factor\n", "I_CEO = 1/(1-alpha)*I_CBO; # Leakage current of BJT in CE mode, mA\n", "\n", "#Results\n", "print \"The base current gain = %2g\"%bta\n", "print \"The leakage current of BJT in CE mode = %4.2f mA\"%(I_CEO/1e-03)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The base current gain = 49\n", "The leakage current of BJT in CE mode = 0.25 mA\n" ] } ], "prompt_number": 15 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 14.15, Page 726" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Variable declaration\n", "R_i = 50; # Dynamic input resistance of PNP transistor, ohm\n", "R_L = 5e+03; # Load resistance in collector circuit, ohm\n", "alpha = 0.96; # Emitter current amplification factor\n", "\n", "#Calculations\n", "A_v = alpha*R_L/R_i; # Voltage gain\n", "A_p = alpha*A_v; # Power gain\n", "\n", "#Results\n", "print \"The voltage gain = %2g\"%A_v\n", "print \"The power gain = %2d\"%A_p\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The voltage gain = 96\n", "The power gain = 92\n" ] } ], "prompt_number": 16 } ], "metadata": {} } ] }