{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Chapter 9 Phase Locked Loop" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 9.1 Pg 284" ] }, { "cell_type": "code", "execution_count": 1, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "The output voltage of switching regulator circuit is = -0.30 V \n", "The output voltage of switching regulator circuit is = 1.50 V \n" ] } ], "source": [ "from __future__ import division\n", "from math import sqrt, pi\n", "# to find output voltage for a constant input signal frequency of 200 KHz\n", "fo = 2*pi*1*10**3 # # KHz/V # VCO sensitivity range 4.1\n", "fc = 500 # # Hz a free running frequency\n", "f1 = 200 # # Hz input frequency\n", "f2 = 2*10**3 # # Hz input frequency\n", "\n", "# the output voltage of PLL is defined as\n", "#Vo = (wo-wc)/ko\n", "ko = fo #\n", "# when i/p locked with o/p wo=wi\n", "# Vo = (wi-wc)/ko #\n", "\n", "#for the i/p frequency fi = 200 Hz\n", "fi = 200 # # Hz\n", "Vo = (((2*pi*fi)-(2*pi*fc))/ko)#\n", "print 'The output voltage of switching regulator circuit is = %0.2f'%Vo,' V '\n", "\n", "#for the i/p frequency fi = 200 Hz\n", "fi = 2*10**3 # # Hz\n", "Vo = (((2*pi*fi)-(2*pi*fc))/ko)#\n", "print 'The output voltage of switching regulator circuit is = %0.2f'%Vo,' V '" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 9.2 Pg 285" ] }, { "cell_type": "code", "execution_count": 2, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "The sum frequency produce by phase detector is = 900.00 KHz \n", "The difference frequency produce by phase detector is = 100.00 KHz \n", "The phase detector frequencies are outside of the low pass filter\n", "The VCO will be in its free running frequency \n" ] } ], "source": [ "from __future__ import division\n", "# to find VCO output frequency\n", "fc = 400 # # KHz a free running frequency\n", "f = 10 # # KHz low pass filter bandwidth\n", "fi = 500 # # KHz input frequency\n", "\n", "# In PLL a phase detector produces the sum and difference frequencies are defined as\n", "\n", "sum = fi+fc #\n", "print 'The sum frequency produce by phase detector is = %0.2f'%sum,' KHz '\n", "\n", "difference = fi-fc #\n", "print 'The difference frequency produce by phase detector is = %0.2f'%difference,' KHz '\n", "\n", "print 'The phase detector frequencies are outside of the low pass filter'#\n", "\n", "print 'The VCO will be in its free running frequency '" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 9.3 Pg 286" ] }, { "cell_type": "code", "execution_count": 3, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "The sensitivity of phase detector Kd is = 0.45 \n", "The maximum control voltage of VCO Vfmax = 1.40 V\n", "The maximum frequency swing of VCO = 35.00 KHz\n", "The maximum range of frequency which lock a PLL is = 15.00 KHz \n", "The maximum range of frequency which lock a PLL is = 85.00 KHz \n", "The maximum and minimum rage between 15 KHz to 85 KHZ \n", "The lock range is = 70.00 KHz \n" ] } ], "source": [ "from __future__ import division\n", "from math import sqrt, pi\n", "# to determine the lock range of PLL\n", "Ko = 25 # # KHz\n", "fo = 50 # # KHz\n", "A = 2 #\n", "Vd = 0.7 #\n", "AL = 1 #\n", "\n", "# the amximum output swing of phase detector \n", "# Vd = Kd*(pi/2) #\n", "\n", "# the sensitivity of phase detector Kd is\n", "Kd = Vd*(2/pi) #\n", "print 'The sensitivity of phase detector Kd is = %0.2f'%Kd,''\n", "\n", "# The maximum control voltage of VCO Vfmax\n", "Vfmax = (pi/2)*Kd*A #\n", "print 'The maximum control voltage of VCO Vfmax = %0.2f'%Vfmax,' V'\n", "\n", "# the maximum frequency swing of VCO\n", "fL = (Ko*Vfmax)#\n", "print 'The maximum frequency swing of VCO = %0.2f'%fL,' KHz'\n", "\n", "# The maximum range of frequency which lock a PLL are\n", "fi = fo-fL #\n", "print 'The maximum range of frequency which lock a PLL is = %0.2f'%fi,' KHz '\n", "\n", "fi = fo+fL #\n", "print 'The maximum range of frequency which lock a PLL is = %0.2f'%fi,' KHz '\n", "\n", "print 'The maximum and minimum rage between 15 KHz to 85 KHZ '\n", "\n", "\n", "# the lock range is\n", "fLock = 2*fL #\n", "print 'The lock range is = %0.2f'%fLock,' KHz '" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 9.4 Pg 286" ] }, { "cell_type": "code", "execution_count": 4, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "The current through the control resistor R is = 0.60 mA \n", "The charging time of capacitor is = 5.00 msec \n", "The total time period of tringular and square wave is = 10.00 msec \n", "The output frequency of VCO is = 0.10 KHz \n" ] } ], "source": [ "from __future__ import division\n", "# to determine the output frequency capacitor charging time of VCO\n", "Vcc = 12 #\n", "Vcs = 6\n", "R = 10 # # K ohm\n", "C = 1 # # uF\n", "\n", "# the current through the control resistor R\n", "i =(Vcc-Vcs)/R #\n", "print 'The current through the control resistor R is = %0.2f'%i, ' mA '\n", "\n", "# The charging time of capacitor \n", "t = (0.25*Vcc*C)/i #\n", "print 'The charging time of capacitor is = %0.2f'%t, ' msec '\n", "\n", "# In VCO the capacitor charging and discharging time period are equal ,so the total time period of tringular and square wave forms can be written as 2*t #\n", "t = ((0.5*Vcc*C)/i)#\n", "print 'The total time period of tringular and square wave is = %0.2f'%t, ' msec '\n", "\n", "# the output frequency of VCO is\n", "fo = 1/t #\n", "print 'The output frequency of VCO is = %0.2f'%fo, ' KHz '" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 9.5 Pg 287" ] }, { "cell_type": "code", "execution_count": 5, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "The charging or discharging time of capacitor is = 25.00 msec \n", "The output frequency of VCO is is = 20.00 Hz \n", "The output frequency of VCO is = 625.00 Kohm\n", "The current through the control resistor R is = 1.60 uA \n", "The capacitor charging current is = 2000.00 V = 0.33Vcc \n" ] } ], "source": [ "from __future__ import division\n", "from math import sqrt, pi\n", "# to design VCO with output square wave pulse time of 50 msec\n", "Vcc =6 #\n", "Vcs = 5 #\n", "R = 22 # #K ohm\n", "C = 0.02 # # uF\n", "t = 50*10**-3 # # sec output square wave pluse\n", "\n", "# In VCO the capacitor charging and discharging time period are equal ,so the total time period of tringular and square wave forms can be written as 2*t #\n", "\n", "\n", "# the charging or discharging time of capacitor \n", "tcap = t/2*1e3 #\n", "print 'The charging or discharging time of capacitor is = %0.2f'%tcap, ' msec '\n", "\n", "# the output frequency of VCO is\n", "fo = 1/t #\n", "print 'The output frequency of VCO is is = %0.2f'%fo, ' Hz '\n", "\n", "# the output frequency of VCO\n", " # fo = (1/4*R*C)#\n", "R = 1/(4*fo*1e3*C*1e-9)/1e3 # Kohm\n", "print 'The output frequency of VCO is = %0.2f'%R, ' Kohm'\n", "\n", "# the current through the control resistor R\n", "i =(Vcc-Vcs)/R*1e3 #\n", "print 'The current through the control resistor R is = %0.2f'%i, ' uA '\n", "\n", "# the capacitor charging current \n", "# (V/t)=(i/C) #\n", "V = (i/C)*tcap #\n", "print 'The capacitor charging current is = %0.2f'%V, ' V = 0.33Vcc '" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 9.6 Pg 289" ] }, { "cell_type": "code", "execution_count": 6, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "The center frequency of VCO is is = 0.17 kHz \n", "The lock range of PLL is = 2.67 KHz/V \n", "The lock range of PLL is = 25.59 k Hz/V \n" ] } ], "source": [ "from __future__ import division\n", "from math import sqrt, pi\n", "# to determine the center frequency of VCO lock and capture range of PLL\n", "R = 15 # # K ohm\n", "C = 0.12 # # uF\n", "Vcc = 12 #\n", "\n", "# the center frequency of VCO fo\n", "fo = (1.2/4/(R*1e3)/(C*1e-6))/1e3#\n", "print 'The center frequency of VCO is is = %0.2f'%fo, ' kHz '\n", "\n", "fo = 4 # # KHz\n", "# the lock range of PLL\n", "fL = (8*fo/Vcc) #\n", "print 'The lock range of PLL is = %0.2f'%fL, ' KHz/V '\n", "\n", "# the capture range of PLL\n", "fc = ((fo-fL)/(2*pi*3.6*10**3*C*1e-6)**(1/2)) #\n", "print 'The lock range of PLL is = %0.2f'%fc, 'k Hz/V '\n", "# ans wrong in the textbook." ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 9.7 Pg 290" ] }, { "cell_type": "code", "execution_count": 7, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "The total time period of VCO is = 5.00 usec \n", "The charging or discharging time of capacitor is = 2.50 usec \n", "The voltage swing of VCO for 12 V supply is = 3.00 V \n", "The lock range of PLL FL is = 0.955 Hz \n", "The capture range is = 437.02 Hz \n" ] } ], "source": [ "from __future__ import division\n", "from math import sqrt, pi\n", "# determine the lock range of the FSK demodulator\n", "Vcc = 12 #\n", "Fvco = 0.25*Vcc #\n", "f = 200*10**3 # # Hz\n", "\n", "\n", "# the total time period of VCO \n", "t = 1/f*1e6 #\n", "print 'The total time period of VCO is = %0.2f'%t, ' usec '\n", "\n", "# In VCO the capacitor charging and discharging time period are equal ,so the total time period of tringular and square wave forms can be written as 2*t #\n", "\n", "\n", "# the charging or discharging time of capacitor \n", "tcap = t/2 #\n", "print 'The charging or discharging time of capacitor is = %0.2f'%tcap, ' usec '\n", "\n", "# the voltage swing of VCO for 12 V supply\n", "Fvco = 0.25*Vcc #\n", "print 'The voltage swing of VCO for 12 V supply is = %0.2f'%Fvco, ' V '\n", "\n", "# The lock range of PLL \n", "#FL = (1/2*pi*f)*(Fvco/tcap)#\n", "FL = (3/(2*pi*f*tcap*1e-6))#\n", "print 'The lock range of PLL FL is = %0.3f'%FL, ' Hz '\n", "\n", "# the capture range \n", "fcap = sqrt(f*FL)#\n", "print 'The capture range is = %0.2f'%fcap, ' Hz '" ] } ], "metadata": { "kernelspec": { "display_name": "Python 2", "language": "python", "name": "python2" }, "language_info": { "codemirror_mode": { "name": "ipython", "version": 2 }, "file_extension": ".py", "mimetype": "text/x-python", "name": "python", "nbconvert_exporter": "python", "pygments_lexer": "ipython2", "version": "2.7.9" } }, "nbformat": 4, "nbformat_minor": 0 }