introduction to adc

7/25/2019 Introduction to ADC

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What is ADC ?

Types of ADCs

HC11 & ADC

Analog to Digital ConverterAnalog to Digital Converter

Denis BISSIERESDenis BISSIERES

Ian CAMPBELLIan CAMPBELL

Yohan LESPYohan LESPERATERAT

Mechatronics - Fall 04Mechatronics - Fall 04


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What is ADC ?

Types of ADCs

HC11 & ADC

ContentsContents

What is ADC ?What is ADC ?

Types of ADCsTypes of ADCs HC11 & ADCHC11 & ADC


3/45

What is ADC ?What is ADC ?

What is ADC ?

Types of ADCs

HC11 & ADC

Definition

Ea!"les of #se Con$ersion "rocess

Acc#rac%


4/45

Most si&nals 'e 'ant to "rocess are analo&

i(e() the% are contin#o#s an* can ta+e aninifinit% of $al#es

,t

t

What is ADC ?

Types of ADCs

HC11 & ADC

DefinitionDefinition


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Di&ital s%ste!s re.#ire *iscrete *i&ital *ata

ADC con$erts an analo& infor!ation into a*i&ital infor!ation

Di&ital S%ste!?Analo& Di&ital

What is ADC ?

Types of ADCs

HC11 & ADC

DefinitionDefinition


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Voltmeter

What is ADC ?

Types of ADCs

HC11 & ADC

Examples of useExamples of use

Cell phone (mirophone!

"V 7.77 V7.77 V

/a$e

oice


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1 ste"s)

Sa!"lin&

2#antification

Co*in&

These o"erations are all "erfor!e* in a sa!eele!ent) the A to D Con$erter

What is ADC ?

Types of ADCs

HC11 & ADC

Conversion proessConversion proess


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s,t3+Ts

Di&ital s%ste! 'or+s 'ith *iscrete states

The si&nal is onl% *efine* at *eter!ine*ti!es

The sa!"lin& ti!es are "ro"ortional to thesa!"lin& "erio* ,Ts

,t

Ts

What is ADC ?

Types of ADCs

HC11 & ADC

Conversion proess# $amplingConversion proess# $ampling

,t

tTs

s,t


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The si&nal can onl% ta+e *eter!ine* $al#esBelon&in& to a ran&e of con$ersion ,"Vr

Base* on n#!5er of 5it co!5inations thatthe con$erter can o#t"#t

6#!5er of "ossi5le states)637n'here n is n#!5er of 5its

Resol#tion) % "Vr'

What is ADC ?

Types of ADCs

HC11 & ADC

Conversion proess# %uantifiationConversion proess# %uantifiation

tTs

s,t

8r2

.,t


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Assi&nin& a #ni.#e *i&ital 'or* to each sa!"le Matchin& the *i&ital 'or* to the in"#t si&nalWhat is ADC ?

Types of ADCs

HC11 & ADC

Conversion proess# Co)ingConversion proess# Co)ing

tT

s

8r2

.,t

097

6-96-7


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The acc#rac% of an ADC can 5e i!"ro$e* 5%increasin&)

The sa!"lin& rate ,Ts The resol#tion ,2

What is ADC ?

Types of ADCs

HC11 & ADC

AurayAuray


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tTs

2

.,t

What is ADC ?

Types of ADCs

HC11 & ADC

AurayAuray

tTs

.,t

:i&her Sa!"lin& rate

t

2

.,t

:i&her Resol#tion


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What is ADC ?

Types of ADCs

HC11 & ADC

$ampling rate$ampling rate

y*uist+$hannon theorem)Mini!#!sa!"lin& rate sho#l* 5e at least t'ice thehi&hest *ata fre.#enc% of the analo& si&nal

fs,-.fmax


14/45

What is ADC ?

Types of ADCs

HC11 & ADC

$ampling rate$ampling rate

Analo& si&nals are co!"ose* of an infinit% ofhar!onics

6ee* to li!it the fre.#enc% 5an* to its #sef#l "art

;se of an analo& filter

ADCAnalo& Di&italAnalo& Analog/ilter

In "ractice) fs< ,1=>ffilter


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What is ADC ?

Types of ADCs

HC11 & ADC

ExampleExample

? 5its con$erter) n3?Ran&e of con$ersion)8r3>

Sa!"lin& ti!e) Ts39!s

Analo&

0

>

0

7>>

Di&ital

6#!5er of "ossi5le states) 637?37>@

Resol#tion) 238r639(> !

Analo& Filter) ffilter < fs> 3 700 :

fain


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Types of ADCsTypes of ADCs

Flash ADC

Si&!a-*elta ADC D#al slo"e con$erter

S#ccessi$e a""roi!ation con$erter

What is ADC ?

Types of ADCs

HC11 & ADC


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"arallel AD

;ses a series of

co!"arators Each co!"arator

co!"ares into a

*ifferent reference$olta&eG startin&' ref3 97 ls5

What is ADC ?

Types of ADCs

HC11 & ADC

/lash ADC/lash ADC


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Co!"arator is one #seof an H"-A!"

+

-

VIN

VREF

VOUT If H#t"#t

I6 REF :i&h

I6J REF Lo'

What is ADC ?

Types of ADCs

HC11 & ADC

/lash ADC/lash ADC


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A)vantagesA)vantages

er% fast

Disa)vantagesDisa)vantages

6ee*s !an% "arts

,7>> co!"aratorsfor ?-5it ADC

Lo'er resol#tion

E"ensi$e Lar&e "o'ercons#!"tion

/lash ADC/lash ADC

What is ADC ?

Types of ADCs

HC11 & ADC


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H$ersa!"le* in"#t si&nal &oes in the inte&rator

H#t"#t of inte&ration is co!"are* to 6D Iterates to "ro*#ce a serial 5itstrea!

H#t"#t is serial 5it strea! 'ith K of 9s "ro"ortionalto in

What is ADC ?

Types of ADCs

HC11 & ADC

$igma+Delta ADC$igma+Delta ADC

Integrator

Digital

low-pass

filter

Sample

decimatorVin +

-

+

-!it

D"#

-

O$ersampler

Serial o%tp%t


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:i&h resol#tion 6o "recision

eternal

co!"onentsnee*e*


Slo' *#e too$ersa!"lin&

What is ADC ?

Types of ADCs

HC11 & ADC

$igma+Delta ADC$igma+Delta ADC


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& T'e sampled signal c'arges a capacitor for a fi(ed amo%nt oftime

& )* integrating o$er time noise integrates o%t of t'e con$ersion,

& T'en t'e "D# disc'arges t'e capacitor at a fi(ed rate w'ile aco%nter co%nts t'e "D#s o%tp%t !its, " longer disc'arge timeres%lts in a 'ig'er co%nt,

tVin tFI. tmeas

What is ADC ?

Types of ADCs

HC11 & ADC

Dual $lope onverterDual $lope onverter


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In"#t si&nal isa$era&e*

reater noisei!!#nit% than other

ADC t%"es :i&h acc#rac%


Slo' :i&h "recision

eternal co!"onentsre.#ire* to achie$e

acc#rac%

What is ADC ?

Types of ADCs

HC11 & ADC

Dual $lope onverterDual $lope onverter


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Sets MSB

Con$erts MSB toanalo& #sin& DAC

Co!"ares ess toin"#t

Set 5it

Test net 5it

S"R D"#

O%t

VIN

-+What is ADC ?

Types of ADCs

HC11 & ADC

$uessive Approximation$uessive Approximation

/// ////

Is Vin0 1 "D# range2

/// ////

If no t'en test ne(t !it


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Ca"a5le of hi&hs"ee*

Me*i#! acc#rac%co!"are* to other

ADC t%"es oo* tra*eoff

5et'een s"ee* an*cost


:i&her resol#tions#ccessi$ea""roi!ation ADCs'ill 5e slo'er

S"ee* li!ite*>Ms"s

What is ADC ?

Types of ADCs

HC11 & ADC

$uessive Approximation$uessive Approximation


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"D# Resol%tion #omparison

/ 3 / 3 4/ 43

Sigma-Delta

S%ccessi$e "ppro(

Flas'

D%al Slope

Resol%tion 5)its6

Type $pee) (relative! Cost (relative!D#al Slo"e Slo' Me*

Flash er% Fast :i&h

S#ccessi$e A""o Me*i#! N Fast Lo'

Si&!a-Delta Slo' Lo'

What is ADC ?

Types of ADCs

HC11 & ADC

ADC Types ComparisonADC Types Comparison


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HC11 & ADCHC11 & ADC

What is ADC ?

Types of ADCs

HC11 & ADC

$truture of the a*uisition

ADCT0 egister

2ption egister

Data onversion

A*uistion


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7E/

"N/

7E

"N

7E4

"N4

7E8

"N8

7E9

"N9

7E3

"N3

7E:

"N:

7E;

"N;

"N"U.

?-!its #"7"#ITIVE D"#

@ITA S">7"TION

RE=ISTER "ND #ONTRO@O

Port E ,analo& in"#t

Analo& M#lti"leer

AD Con$erter

Res#ltRe&isterInterface

ADR9 - res#lt 9

ADR7 - res#lt 7

ADR1 - res#lt 1

ADR4 - res#lt 4

? channel5it in"#t

RL 3 0 $olts

R: 3 > $olts

Di&ital in"#t on P

What is ADC ?

Types of ADCs

HC11 & ADC

$truture of the a*uisition$truture of the a*uisition


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CCF CB CA

ADCTL ,9010Reset to) 0 0 # # # # # #

0 SCAN MULT CD CC

M;LT- Sin&le or !#lti"le channel

0) Sa!"le a sin&le channel ,fo#r ti!es9) Sa!"le fo#r channels

CDGCCGCBGCA - Channel selectionIf M;LT is 0G then CC-CA 5its s"ecif% the channel

If M;LT is 9G then CC s"ecifies the &ro#")

0) Sa!"le A60-A61G 9) Sa!"le A64-A6O

CD is reser$e* for factor% test #se

CCF- Con$ersion Co!"lete Fla&Set 'hen all fo#r con$ersions are co!"lete

Cleare* 5% 'ritin& to ADCTL - starts the net con$ersion

SCA6- Contin#o#s scan !o*e

0) Ta+e one set of fo#r con$ersions an* sto"

9) Contin#all% "erfor! ne' con$ersions

What is ADC ?

Types of ADCs

HC11 & ADC

ADCT0 egisterADCT0 egister


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4 channels arecontin#o#sl%

con$erte*( ADR9-ADR4 o$er'ritten

Hne channel iscontin#o#sl%

con$erte*( ADR9-ADR4 o$er'ritten

Contin#o#sCon$ersion

,SCA6 3 9

4 channelscon$erte* once(The res#lts arestore* in ADR9-

ADR4

Hne channelcon$erte* 4 ti!es

consec#ti$el%( Theres#lts are store* in

ADR9-ADR4

Sin&leCon$ersion,SCA6 3 0

M#lti"leChannel

,M;LT 3 9

Sin&le Channel

,M;LT 3 0

ADRK Beha$ior

What is ADC ?

Types of ADCs

HC11 & ADC



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09714>@O

What is ADC ?

Types of ADCs

HC11 & ADC

PHRT E

AD Con$erterRes#ltRe&isterInterface

ADR9 N Res#lt9

ADR7 N Res#lt7

ADR1 N Res#lt1

ADR4 N Res#lt4

$ingle Channel$ingle Channel


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0

What is ADC ?

Types of ADCs

HC11 & ADC

PHRT E

AD Con$erterRes#ltRe&isterInterface

ADR9 N Res#lt9

ADR7 N Res#lt7

ADR1 N Res#lt1

ADR4 N Res#lt4

3ultiple Channels3ultiple Channels

9714>@O


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E #locC c*cles

#on$ersion Se%ence

"D#T ADR7

0 9 9 0 PE@ ADR1

0 9 9 9 PEO ADR4

9 0 0 0 Reser$e* ADR9


9 0 9 0 Reser$e* ADR19 0 9 9 Reser$e* ADR4

9 9 0 0 : ADR9

9 9 0 9 L ADR7

9 9 9 0 97 : ADR1


"BD #'annel "ssignment

799; Reference >an%al



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ADRK Beha$ior

What is ADC ?

Types of ADCs

HC11 & ADC

Sin&le Channel The Channel is selecte* 5% CA4 C54

,M;LT 3 0 CC

M#lti"le Channel The &ro#" of Channels is selecte* 5%,M;LT 3 A CConl%



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ADP; CSEL IR2E DLY CME CR9 CR0

H"tions Re&ister ,901

ADP; 3 AD "o'er #"

CSEL 3 Cloc+ Select

IR2E 3 Confi&( IR2

DLY 3 Ena5le start-#" *ela%

CME 3 Cloc+ Monitor

Bit 7 3 not i!"le!ente*

CR9 3 CHP Ti!er Rate

CR7 3 CHP Ti!er Rate

)it /9 8 4:; 3

What is ADC ?

Types of ADCs

HC11 & ADC

2ption egister2ption egister


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ADP;- AD Char&e P#!"0) T#rn off the AD

9)T#rn on the AD ,5% ena5lin& the char&e "#!"

6ote) /ait at least 900 !icrosecon*s 5efore #sin& the AD

,This is 700 c%cles at a 7M: E-cloc+

CSEL - AD Cloc+ select0) ;se the E-cloc+ for the AD

9) ;se a s"ecial internal AD cloc+ that r#ns at aro#n* 7M:

6ote) If the E-cloc+ is O>0Q: or hi&herG CSEL sho#l* 5e 0(

Hther'ise CSEL sho#l* 5e 9(

D067 Delay

0 3 6o *ela% is #se* an* MC; res#!es 'ithin a""ro( 4 c%cles(

9 3 4000 E cloc+ c%cle *ela% i!"ose* to allo' cr%stal sta5iliation

What is ADC ?

Types of ADCs

HC11 & ADC

2ption egister2ption egister


40/45

/,/4G/,/43?/,/3:/,/8/,4/:8/,943/,?43H,:3Volts

586

/,/G3/,/8G/,/;?/,3:4/,843/,:43,43/4,3//Volts

546

/,8G/,;?,3:8,4:,434,3433/ 56

)it /4893:)it ;

56 of VRA-VR


41/45

MA )

(9999 9999 3 (FF9@ 3 0(@01O>90 3 (@01

Resol#tion )

(0000 0009 3 (099@ 3 0(0010@7>90 3 0(10@

MI6 )

(0000 0000 3 09@ 3 09030

What is ADC ?

Types of ADCs

HC11 & ADC

Data onversionData onversion


42/45

0 J3 analo& in"#t J3 >

Char&e "#!" allo's R: !a @-O

RL an* R: con$ert to 00 an* FF

Di&ital in"#t of Port E "ins not reco!!en*e*

*#rin& AD sa!"le ti!e

So!e a**itional notes)What is ADC ?

Types of ADCs

HC11 & ADC

Data onversionData onversion

A*uisitionA*uisition


43/45

What is ADC ?

Types of ADCs

HC11 & ADC

A*uisitionA*uisition

ADPU CR1 CR2HPTIH6 ,901 CSEL IREQ DLY CME 0

CCF CB CAADCTL ,9010 0 SCAN MULT CD CC

O7TION EKU L/8G"D#T< EKU L/8/"DR EKU L/8OR= L/9/

U


44/45

What is ADC ?

Types of ADCs

HC11 & ADC

A*uisitionA*uisitionS%!ro%tine o%tp%t to t'e screen t'e decimal e%i$alence of t'e stacC

OR= L9///

7U


45/45

What is ADC ?

Types of ADCs

HC11 & ADC %uestions ?%uestions ?

introduction to adc

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