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7/23/2019 Analog to Digital Converters Presentation
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Analog-to-digital converterAnalo
g-to-digital converter
Prepared by:Prepared by:
Selah al-BattahSelah al-Battah
Mohammed Al-khabbazMohammed Al-khabbaz
Atiyah AlnakhliAtiyah Alnakhli
Ali DumyatiAli Dumyati
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IntroductionIntroduction
--Signal in real !orld" light# oundSignal in real !orld" light# ound$$
--%hen you can a picture !ith a canner !hat the%hen you can a picture !ith a canner !hat thecanner i doing&& 'AD()canner i doing&& 'AD()
It i taking the analog in*ormation provided by theIt i taking the analog in*ormation provided by thepicture 'light) and converting into digitalpicture 'light) and converting into digital$$
--%hen you record your voice on your computer%hen you record your voice on your computer##
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Introduction cont,dIntroduction cont,d
--Since analog ignal can aume any value# noieSince analog ignal can aume any value# noiei interpreted a being part o* the original ignal$i interpreted a being part o* the original ignal$
Digital ytem# on the other hand# can onlyDigital ytem# on the other hand# can only
undertand t!o number# zero and one$ Anythingundertand t!o number# zero and one$ Anythingdi**erent *rom thi i dicardeddi**erent *rom thi i dicarded$$
--ere !e need a tranlator *rom analog to digital$ere !e need a tranlator *rom analog to digital$.he device !hich play thi /ob are called analog.he device !hich play thi /ob are called analog
to digital converterto digital converter$$
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Analog-to-digital converterAnalog-to-digital converter
--An analog-to-digital converter (abbreviated ADC,An analog-to-digital converter (abbreviated ADC,
A/D or A to D)A/D or A to D)i an electronic circuit that converti an electronic circuit that convert
continuou ignal to dicrete digital numbercontinuou i
gnal to dicrete digital number..
--.he digital output may be uing di**erent coding.he digital output may be uing di**erent codingcheme# uch a binary and t!o, complementcheme# uch a binary and t!o, complement
binary$ o!ever# ome non-electronic or onlybinary$ o!ever# ome non-electronic or only
partially electronic device# uch a ha*t encoder#partially electronic device# uch a ha*t encoder#can alo be conidered a AD(can alo be conidered a AD($$
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Techniques of ACDTechniques of ACD
--.here are variou techniue o* A3D.here are variou techniue o* A3D
converionconverion::
44$$including *lahincluding *lah$$22$$ucceive appro5imationucceive appro5imation$$
++$$Delta-encodedDelta-encoded$$
00$$IntegratorIntegrator$$
11$$delta igma or modulatordelta igma or modulator$$
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A direct conversion ADC or flash ADCA direct conversion ADC or flash ADC
-A direct converion i very *at# but uually ha-A direct converion i very *at# but uually haonly 7 bit o* reolution '216 comparator) oronly 7 bit o* reolution '216 comparator) or*e!er# a it need a large# e5penive circuit$ AD(*e!er# a it need a large# e5penive circuit$ AD(
o* thi type have a large die ize# a high inputo* thi type have a large die ize# a high inputcapacitance# and are prone to produce mitakecapacitance# and are prone to produce mitakeon the output 'by outputting an out-o*-euenceon the output 'by outputting an out-o*-euencecode)$code)$
--e5ample:e5am
ple:.hey are o*ten ued *or video or other *at ignal$.hey are o*ten ued *or video or other *at ignal$
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A ucceive appro5imation AD(A ucceive appro5imation AD(
.hi type ue a comparator to re/ect range o*.hi type ue a comparator to re/ect range o*
voltage# eventually ettling on a *inal voltage range$voltage# eventually ettling on a *inal voltage range$
.he !ay ucceive appro5imation !ork i through.he !ay ucceive appro5imation !ork i through
contantly comparing the input voltage to a kno!ncontantly comparing the input voltage to a kno!nre*erence voltage until the bet appro5imation ire*erence voltage until the bet appro5imation i
achieved$ At each tep in thi proce# a binaryachieved$ At each tep in thi proce# a binary
value o* the appro5imation i tored in a ucceivevalue o* the appro5imation i tored in a ucceive
appro5imation regiter 'SA9)$ the SA9 ue aappro5imation regiter 'SA9)$ the SA9 ue are*ernce voltage *or converionre*ernce voltage *or converion$$
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AA delta-encoded ADCdelta-encoded ADC
- A delta-encoded AD( ha an up-do!n- A delta-encoded AD( ha an up-do!n countercounterthat *eed athat *eed a'DA()$ .he input ignal and the DA( both go to a'DA()$ .he input ignal and the DA( both go to acomparator$ .he comparator control the counter$ .hecomparator$ .he comparator control the counter$ .hecircuit ue negativecircuit ue negative *eedback*eedback*rom the comparator to*rom the comparator to
ad/ut the counter until the DA(, output i cloe enoughad/ut the counter until the DA(, output i cloe enoughto the input ignal$ .he number i read *rom the counter$to the input ignal$ .he number i read *rom the counter$
- Delta converter have very !ide range# and highDelta converter have very !ide range# and highreolution # but the converion time i dependent on thereolution # but the converion time i dependent on the
input ignal level$input ignal level$
- Delta converter are o*ten very good choice to read real-Delta converter are o*ten very good choice to read real-!orld ignal$$!orld ignal$$
http://en.wikipedia.org/wiki/Counterhttp://en.wikipedia.org/wiki/Counterhttp://en.wikipedia.org/wiki/Feedbackhttp://en.wikipedia.org/wiki/Feedbackhttp://en.wikipedia.org/wiki/Feedbackhttp://en.wikipedia.org/wiki/Counter7/23/2019 Analog to Digital Converters Presentation
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IntegratorIntegrator
An integratorAn integrator ADCADC'alo called'alo called ramp-compareramp-compare## dual-dual-slopeslopeoror multi-slopemulti-slopeAD() produce aAD() produce a a!-tooth ignala!-tooth ignal
that ramp up# then uickly *all to zero$ %hen the rampthat ramp up# then uickly *all to zero$ %hen the ramp
tart# a timer tart counting$ %hen the ramp voltagetart# a timer tart counting$ %hen the ramp voltage
matche the input# a comparator *ire# and the timer, valuematche the input# a comparator *ire# and the timer, value
i recorded$ .imed ramp converter reuire the leati recorded$ .imed ramp converter reuire the leatnumber o*number o* tranitortranitor$$
- .he ramp time i enitive to temperature&&- .he ramp time i enitive to temperature&&
.here are t!o olution: ue a clocked counter driving a.here are t!o olution: ue a clocked counter driving a
DA(DA(and then ue the comparator to preerve theand then ue the comparator to preerve the
counter, value# or calibrate the timed ramp$counter, value# or calibrate the timed ramp$
http://en.wikipedia.org/wiki/Sawtooth_wavehttp://en.wikipedia.org/wiki/Sawtooth_wavehttp://en.wikipedia.org/wiki/Transistorhttp://en.wikipedia.org/wiki/Transistorhttp://en.wikipedia.org/wiki/Digital-to-analog_converterhttp://en.wikipedia.org/wiki/Digital-to-analog_converterhttp://en.wikipedia.org/wiki/Digital-to-analog_converterhttp://en.wikipedia.org/wiki/Transistorhttp://en.wikipedia.org/wiki/Sawtooth_wave7/23/2019 Analog to Digital Converters Presentation
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AA Sigma-Delta ADCSigma-Delta ADC
- Alo kno!n a a Delta-Sigma AD( over ample the- Alo kno!n a a Delta-Sigma AD( over ample the
deired ignal by a large *actor and *ilter the deireddeired ignal by a large *actor and *ilter the deired
ignal band$
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9eolution9eolution
--.he reolution o* the converter indicate the number o*.he reolution o* the converter indicate the number o*
dicrete value it can produce over the range o* voltagedicrete value it can produce over the range o* voltage
value$ It i uually e5preed in 'bit)$ =or e5ample# anvalue$ It i uually e5preed in 'bit)$ =or e5ample# an
AD( that encode an analog input to one o* 216 dicreteAD( that encode an analog input to one o* 216 dicrete
value ';$$$211) ha a reolution o* eight bit# ince 2>7 ?value ';$$$211) ha a reolution o* eight bit# ince 2>7 ?
216216$$
--9eolution can alo be de*ined electrically# and e5preed in9eolution can alo be de*ined electrically# and e5preed in
volt$ .he voltage reolution o* an AD( i eual to it overallvolt$ .he voltage reolution o* an AD( i eual to it overall
voltage meaurement range divided by the number o*voltage meaurement range divided by the number o*
dicrete valuedicrete value$$
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(ommercial analog-to-digital converter(ommercial analog-to-digital converter
--.hee are uually integrated circuit.hee are uually integrated circuit$$
--Mot converter ample !ith 6 to 20 bit o* reolution# andMot converter ample !ith 6 to 20 bit o* reolution# and
produce le than 4 mega ample per econd$ It i rare toproduce le than 4 mega ample per econd$ It i rare to
get more than 20 bit o* reolution$ Mega ampleget more than 20 bit o* reolution$ Mega ampleconverter are reuired in digital video camera# videoconverter are reuired in digital video camera# video
capture card# and .@ tuner card to convert *ull-peedcapture card# and .@ tuner card to convert *ull-peed
analog video to MP< digital video *ileanalog video to MP< digital video *ile$$
--(ommercial converter uually have ;$1 to 4$1 CSB error(ommercial converter uually have ;$1 to 4$1 CSB error
in their outputin their output$$
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Application to music recordingApplication to music recording
- AD( are integral to much current muicAD( are integral to much current muic
reproduction technology# ince much muicreproduction technology# ince much muic
production i done on computer" even !henproduction i done on computer" even !hen
analog recording i ued$analog recording i ued$- An AD( i till needed to create the P(M dataAn AD( i till needed to create the P(M data
tream that goe onto a compact dictream that goe onto a compact dic$$
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Other applicationsOther applications
- AD converter are ued virtually every!here !here anAD converter are ued virtually every!here !here an
analog ignal ha to be proceed# tored# or tranportedanalog ignal ha to be proceed# tored# or tranported
in digital *orm$ =at video AD( are ued# *or e5ample# inin digital *orm$ =at video AD( are ued# *or e5ample# in
.@ tuner card$ Slo! on-chip 7# 4;# 42# or 46 bit AD( are.@ tuner card$ Slo! on-chip 7# 4;# 42# or 46 bit AD( are
common in microcontroller$common in microcontroller$
- @ery *at AD( are needed in digital ocillocope# and are@ery *at AD( are needed in digital ocillocope# and are
crucial *or ne! application like o*t!are de*ined radiocrucial *or ne! application like o*t!are de*ined radio
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uetionuetion&&&&