Bao Cao Thiet Ke

7/31/2019 Bao Cao Thiet Ke

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I HC CNG NGH THNG TIN & TRUYN THNGKhoa in T Vin Thng

Mn : Thit k mch logic & analog

Ging vin: Trn Th Xun

Thai Nguyn 12-2011

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Thit k mch m 4 bit khng ng bs dng trig JK.

Gio vin hng dn: Trn Th Xun

B mn:in t vin thng.

Cc thnh vin trong nhm:

1. Phm Vn Tm

2. Vng S Tn

3. Nguyn Thanh H

4. Hong Vn Hip

5. Nguyn Quang Huy

6. Nguyn Vn Dinh

Lp N03-DTVTK8B

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LI NI UNgy nay, vi s pht trin khng ngng ca khoa hc k thut, vic ng dngcc linh kin bn dn phn no gim bt c gi thnh sn phm bng cclinh kin ri. ng dng mn k thut s vo thit k cc b phn thit thc hngngy gip chng ta hiu c mn k thut s lm g v c ng dng vo u.

Mch m cng c ng dng v phc v rt nhiu trong cuc sng ca chngta.Sau y nhm chng em xin thit k mt mch m 4 bit khng ng b dngtrig JK. y l mch m rt thng dng trong k thut s l c s thit kcc b m khc.Trong ti cn nhiu thiu st, rt mong c s gp ca c gio v cc bn c hon thin hn.!.

Nhm thc hin!

Thi Nguyn, thng 12, nm 2011.

I./ L THUYT C BN.

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1- Tng quan.Ni n bi ton m cng ta ngh ngay n vic l m xung cc IC s, sm sn ln hay sn xung ca xung u vo cn m. m y l mxung vung) mi gi tr sn ln hay sn xung ca xung c a vo ICm v c gii m nh IC gii m sau m ha v hin th ra LED 7thanh.Mch m t 00-99 gm 4 khi chnh :

- Khi to dao ng (s dng IC555)- Khi m nh phn 4 bit. (s dng IC74LS76).- Khi gii m BCD (s dng IC74LS47).- Khi hin th kt qu.(s dng LED 7 on).

- Trong bi tp chng em s dng led n hin th m khng sdng Led 7 on v vy mch khng s dng IC gii m 74ls47

2- Cc linh kin s dng trong mch.1. IC NE555 (1con)1.1 Tng Qut

NE555 l mt loi linh kin khl ph bin by gi vi vic d

dng to c xung vung v cth thay i tn s ty thch, vis mch n gin,iu chc rng xung. N cng dng hu ht vo cc mchto xung ng ct hay l nhngmch dao ng khc.y l linhkin ca hng CMOS snxut .Sau y l bng thng sca NE555 c trn th trng :+ in p u vo : 2 - 18V( Ty tng loi ca 555 :LM555, NE555, NE7555..)+ Dng in cung cp : 6mA -15mA+ in p logic mc cao : 0.5 - 15V

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+ in p logic mc thp : 0.03 - 0.06V+ Cng sut ln nht l : 600mW

1.2 Cc chc nng ca 555:+ L thit b to xung chnh xc+ My pht xung+ iu ch c rng xung (PWM)+ iu ch v tr xung (PPM) (Hay dng trong thu pht hng ngoi)

1.3 S cc ChnIC NE555 N gm c 8 chn.

+ Chn s 1(GND):

cho ni GND ly dng cp cho IC hay chn cn gi l chn chung.+ Chn s 2(TRIGGER): y l chn u vo thp hn in p so snh vc dng nh 1 chn cht hay ng vo ca 1 tn so p.Mch so snh ydng cc transitor PNP vi mc in p chun l 2/3Vcc.+ Chn s 3(OUTPUT): Chn ny l chn dng ly tn hiu ra logic. Trngthi ca tn hiu ra c xc nh theo mc 0 v 1. 1 y l mc cao n tngng vi gn bng Vcc nu (PWM=100%) v mc 0 tng ng vi 0V nhngm trong thc t mc 0 ny ko c 0V m n trong khong t (0.35->0.75V) .

+ Chn s 4(RESET): Dng lp nh mc trng thi ra. Khi chn s 4 nimasse th ng ra mc thp. Cn khi chn 4 ni vo mc p cao th trng thing ra ty theo mc p trn chn 2 v 6.Nhng m trong mch to c daong thng hay ni chn ny ln VCC.+ Chn s 5(CONTROL VOLTAGE): Dng lm thay i mc p chuntrong IC 555 theo cc mc bin p ngoi hay dng cc in tr ngoi cho niGND. Chn ny c th khng ni cng c nhng m gim tr nhiu ngi

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ta thng ni chn s 5 xung GND thng qua t in t 0.01uF n 0.1uF cct ny lc nhiu v gi cho in p chun c n nh.+ Chn s 6(THRESHOLD) : l mt trong nhng chn u vo so snh inp khc v cng c dng nh 1 chn cht.+ Chn s 7(DISCHAGER) : c th xem chn ny nh 1 kha in t v chuiu khin bi tng logic ca chn 3 .Khi chn 3 mc p thp th kha nyng li.ngc li th n m ra. Chn 7 t np x in cho 1 mch R-C lc IC555 dng nh 1 tng dao ng .+ Chn s 8 (Vcc): Khng cn ni cng bt l chn cung cp p v dng choIC hot ng. Khng c chn ny coi nh IC cht. N c cp in p t 2V-->18V (Ty tng loi 555 nh thp nht l con NE7555)1.4 Cch tnh tn s v rng xung

Khi thay i cc in tr R1, R2 v cc gi tr ca t C1 s thu c giaong c tn s v rng xung nh mun theo cng thc:

T = 0.7 * (R1 + 2R2) x C1 v f = 1.4/ (R1 + 2R2) x C1). Trong :

T: Thi gian chu k ton phn (s).

f : Tn s dao ng (Hz).

R1, R2 : in tr (Ohm).

C1: T in (Fara).

T= Tm + Ts

Tm = 0.7 * (R1 + R2) x C1

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Tm : Thi gian in mc cao.

Ts = 0.7 * R2 * C1

Ts : Thi gian in mc thp.

T cc cng thc trn ta c th to ra xung c rng Tm v Ts bt k.

Xung c to ra c: T = Tm + Ts v f = 1/T

2. IC74LS76(JK-FF)- S lng: 2 con2.1 Tng quan v Flip flopFF l mch c kh nng lt li trng thi ng ra tu theo s tc ng thch hpca ng vo, iu ny c ngha quan trng trong vic lu tr d liu trongmch v xut d liu ra khi cn.

C nhiu loi flip flop khc nhau, chng c s dng rng ri trong nhiu ngdng. Cc mch FF thng c k hiu nh sau

Hnh 2.1 K hiu FF

Nu cc ng vo s quyt nh ng ra l ci g th ng ng h ck li ch ra rngkhi no mi c s thay i . Chn Ck c th tc ng mc thp hay mc caotu vo cu trc bn trong ca tng IC FF, do vi mt IC FF c nh th chc mt kiu tc ng v ch mt m thi, v d vi IC 74112 ch c mt cchtc ng l xung Ck tc ng theo cnh xung.

Cc loi FF

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Hnh 2.2 K hiu khi ca 4 loi FF ny bi cnh ln Ck

2.2 JK-FF

FF JK b sung thm trng thi cho FF RS ( trnh trng thi cm)

Hnh 2.3 Dng sng minh ho cho FF JK

Nhn thy u vo J, K iu khin trng thi ng ra theo ng nh cch m SR lm tr 1 im l khi J = K = 1 th trng thi cm c chuyn thnh trng

thi ngc li ( vi J = K = 0 ). N cn gi l ch lt ca hot ng.T dng sng c th thy rng ng ra FF khng b nh hng bi sn xung

ca xung ck cc u vo J K cng khng c tc ng tr khi xy ra tc ng lnca Ck

Cn cu to bn trong ca FF JK kch bng cnh sn s nh sau :

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http://void%280%29/http://huongnghiepviet.com/codientu/ki_thuat_cdt/dien_tu/vi_mach_so/chuong_3/02_ffl_01.htm#FF%20Dhttp://huongnghiepviet.com/codientu/ki_thuat_cdt/dien_tu/vi_mach_so/chuong_3/02_ffl_01.htm#FF%20Thttp://huongnghiepviet.com/codientu/ki_thuat_cdt/dien_tu/vi_mach_so/chuong_3/02_ffl_01.htm#FF%20JK


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Hnh 2.3 Cu trc mch ca FF JK

-74LS76 l 1 IC cha 2 FF JK trong cng mt v, ng ng h clock (k hiu

l CP: Clock Pulse)tc ng cnh xung; n u c c 2 ng vo trc tip lPreset (k hiu chn l SD) v Clear (k hiu chn l CD), trong cu to mch nhhnh di, chng u c a vo tng nand u.

Hnh 2.4 K hiu khi v cu to bn trong ca 74LS76

Bng trng thi hot ng ca 74LS76

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3. IC74LS86(XOR)

S chn.

Cu trc bn trong.

Input OutputA B YL L LL H HH L HH H L

Y = AB + AB = A B

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4. in tr

- in tr l mt linh kin c tnh cn tr dng in v lm mt s chc

nng khc ty vo v tr in tr trong mch in.- Cu to: in tr c cu to t nhng vt liu c in tr sut cao nhlm bng than, magie kim loi Ni-O2, oxit kim loi, dy qun. biu thgi tr in tr. Ngi ta dung cc vng mu biu th gi tr in tr.

- K hiu: R- Cch c tr s in tr 4 vng mu: Gi tr in tr thng c th hinqua cc vch mu trn thn in tr, mi mu i din cho mt s. Mu en:s 0, mu nu: s 1, mu : s 2, mu cam: s 3, mu vng: s 4, mu lc:s 5, mu lam s 6, mu tm s 7, mu xm: s 8, mu trng: s 9.

- Nhn trn thn in tr, tm bn c vch mu nm st ngoi cng nht,vch mu v vch mu th hai, k n c dng xc nh tr s camu..

- Vch th ba l vch xc nh nhn t ly tha: 10(gi tr ca mu) . Gitr ca in tr c tnh bng cch ly tr s nhn vi nhn t lythaGi tr in tr = tr s x nhn t ly tha)- Phn cui cng: (khng cn quan tm nhiu)lvch mu nm tch bit vi

ba vch mutrc, thng c mu hong kim hoc mubc, dng xcnh sai s ca gi tr intr, hong kim l 5%, bc l 10%.

5. T in.

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-T in l linh kin c kh nng tch in. T in cch in vi dng inmt chiu v cho dng in xoay chiu truyn qua.

-T in c chia lm hai loi chnh: loi khng phn cc v loi c phncc.-Loic phn cc thng c gi tr ln hn loi khng phn cc, trn hai chnca loi phn cc c phn bit chn ni m, ni dng r rng, khi gn t c

phn cc vo mch in, nu gn ngc chiu m dng, t phn cc c th bh v hot ng sai. Ngoi ra ngi ta cn gi tn t in theo vt liu lm t,v d: t gm, t giy, t ha...-Hnh dng: t in c kh nhiu hnh dng khc nhau.K hiu: c k hiu l Cn v ca t in

- n v ca t in l Fara, 1 Fara c tr s rt ln v trong thc t ngi tathng dng cc n v nh hn nh+ P(Pico Fara) 1 Pico = 1/1000.000.000.000 Fara (vit gn l 1pF)+ N(Nano Fara) 1 Nano = 1/1000.000.000 Fara (vit gn l 1nF)+ MicroFarra 1 Micro = 1/1000.000 Fara (vit gn l 1F)

=> 1F = 1000nF = 1.000.000 PfCch c gi tr ca t in:- c trc tip trn thn in tr, v d 100F (100 micro Fara)

Nu l s dng 103J, 223K, 471J vv th n v l pico, hai s u gi nguyn ,s th 3 tng ng s lng s 0 thm vo sau( ch J hoc K cui k k hiucho sai s).-V d 1:103J s l 10000 pF (thm vo 3 s 0 sau s 10) = 10 nF.

6. Led n.(8 con)

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-LED (vit tt ca Light Emitting Diode, c nghal it pht quang) l cc it c kh nng pht ra nh sng hay tia hngngoi. Cng ging nh it, LED c cu to t mt khi bn dn loi p

ghp vi mt khi bn dn loi n.-Chc nng : hin th s nh phn..Led sng=1, led tt=0

7 .Ngoi ra cn c board ng, dy ni..v trong bi tp chng em s dngled n gim chi ph..Nu s dng led 7 on hin th th cn s dngthm cc linh kin :

. n LED 7 on(1 con)

Led 7 on l mt linh kin hin th m 7 on chuyn dng, n hin th 16gitr tng ng vi m BCDLed 7 on c 2 loi: loi chung anot v loi chungcatot.Led 7 on cng c rt nhiu mu sc khc nhau.Trong ti ny c sdng 2 led 7 on chung anot hin th s

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.IC 74LS47- Mch gii m c s dng ph bin nht l dng hin th kt qu dngch s. Do c nhiu loi n hin th v nhiu loi m s khc nhau ln cnhiu mch gii m khc nhau.

V d: gii m 3 ng ra 8 ng, gii m BCD ra thp phn...IC74LS47 l loi IC gii m BCD sang led 7 on. Mch gii m BCD sang led7 on l mch gii m phc tp v mch phi cho nhiu ng ra ln cao hocxung thp( ty vo loi n led l anod chung hoc catot chung) lm ccn sng ln cc s hoc k t. IC 74LS47 l loi IC tc ng mc thp cng ra cc thu h v kh nng nhn dng cao thc trc tip vo cc

n led 7 on loi anod chung.a_hnh dng v kch thc chn ngoi thc t:

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*S chn ca IC74LS47.y l IC gii m t BCD sang LED 7 a n vi 4 chn u vo v 7 chn ura vi chc nng ca cc chn nh sau:

- Chn 1,2,6,7: Chn d liu BCD vo d liu ny c ly t IC m.-Chn :9,10, 11,12,13,14,15: Cc chn ra tc ng mc thp 0 v c

ni vi LED 7 thanh-Chn 8 :l chn ni t GND.-Chn 16: Chn ni ngun 5V.-Chn 4: Chn ny c ni ln Vcc.-Chn 5: Ng vo xa dn sng RBI c khng hay ni ln cao khi

khng c dng xa s 0 (s 0 trc s c ngha hay s 0 tha bn tri duchm thp phn).

-Chn 3: Chn ny cng c ni ln ngun Vcc.

b_S logic ca 74LS47.

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c_Bng trng thi ca IC74LS47.

*Nguyn l hot ng:Nhn bng chn l trn ta thy vi 4 u vo sau khi gii m n cho ra 15 gi trca LED 7 on v hin th ln c LED 7 on.S hot ng ca mch c th hin bng chn l, trong i vi cc ng

ra H l tt v L l sng . Ngha l nu 74LS47 thc n led 7 on th cc ona,b,c,d,e,f,g ca n s sng hay tt ty vo ng ra tng ng ca 74LS47 la Lhay H nn n phi dng LED anod chung.

Ng vo xa RBI c 0 hay ni ln mc 1 dng xa s 0 (s 0 tha phasau s thp phn hay s 0 trc s c ngha). Khi RBI v cc ng vo A,B,C,D mc 0 nhng ng vo LT mc 1 th cc ng ra u tt v ng vo xa dnsng RBO xung mc thp.Khi ng vo BI/RBO ni ln mc 1 v LT mc 0 th ng ra u sng.Kt qu l khi m s nh phn 4 bit vo c gi tr thp phn t 0-15 n led hinth cc s nh hnh bn di

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II. Cc bc thc hin mch..

1.V m phng trn proteus

2. Sau khi mch chy trn m phng ta thc hin v mch in tren proteushoc orcard

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3. Sau l mch in ln board ng ri ngm dung dch v khoan l hn linhkin v test th mch

III. Nguyn l hot ng ca mch

Mch m ln

-Hnh di y trnh by mt mch m gm 4 FF T mc ni tip. Cc ngvo T (hay J=K) ca c 4 tng FF u trng hay ni ln +Vcc. Xung cn mc a vo ng ck tc ng cnh xung ca tng FF u tin (n c th lmt chui xung vung c chu k khng c nh)

-Cc ng ra Q ln lt c ni ti ng vo m ck ca tng sau n (nu c).Chng c t tn l Q0 (LSB), Q1, Q2, Q3 (MSB)

Hnh 3.1 B m nh phn 4 bit khng ng b c bn

Hnh 3.2 Gin thi gian xung ca ng vo v cc ng ra b m :

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- Mch m thng hot ng trng thi ban u l 0000 do mt xung tcng mc thp s c p vo ng Cl ca cc tng FF t trng thi ng ral 0000.

- Khi xung m ck tc ng cnh xung u tin th Q0 lt trng thi tc lQ0 = 1. cnh xung th 2 ca xung ck, Q0 li lt trng thi mt ln na, tc lQ0 = 0. Nh vy c sau mi ln tc ng ca ck Q0 li lt trng thi mt ln, sau2 ln ck tc ng, Q0 lp li trng thi ban u, do nu xung ck c chu k lT v tn s l f th xung ng ra Q0 s c chu k l 2T v tn s cn 1/2f. Nh vyxung m ck c chia i tn s sau 1 tng FF.

- Do Q0 li tr thnh ng vo xung m ca FF th 2 (FF B) nn tng t tnnh vy fQ1 bng mt na fQ0. Vi 4 tng FF th

fQ3 = 1/2fQ2 = 1/4fQ1 = 1/8fQ0 = 1/16f

-Nh vy vi 4 FF ta c 16 trng thi logic ng ra t 0000(010) xung m utin n 1111 (1510) xung m th 16, tc l tr thp phn ra bng s xungm vo v v vy y l mch m nh phn 4 bit (c 4 tng FF, tn s cchia i sau mi tng)

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Bng s tht ca mch m nh phn 4 bit nh sau :

Sxung

vo

M s ra sau khi cxung vo

Tr thpphn ra

Q3 Q2 Q1 Q0Xo

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Nhn vo gin xung v bng trng thi hot ng ca mch m ny ta thyrng khng phi lc no cc trng thi logic cc ng ra u thay i theo nhpxung m ck u vo nn y ch l mch m khng ng b.

Mch m xung

trc l mch m ln ln lt chia 2 tn s, s h 10 ra tng ng l t 0n 15. Cng c khi cn mch m xung t 15 xung 0 chng hn, cch nimch s nh th no?

Hnh di trnh by cu trc mch m xung nh phn 4 bit. Ng ra Q ln ltca tng trc s c ni n ng vo ck ca tng sau . Xung m ck vntc ng mc thp

Hnh 3.3 Mch m xung 4 bit khng ng b

Cc ng ra v cch thc xo mch, a xung vo ging nh trc. Ng ra Qca tng FF u di trng thi i cnh xung ca xung vo cc ng ra khci trng thi cnh xung ca ng ra Q', tc l cnh ln ca ng ra Q0 ca FFk trc. Dng sng ng vo v cc ng ra cng vi mc logic sau mi xungvo v kt qu s m c trnh by nh hnh di y. rng sau xungck u tin th mch se m ngay ln s m cao nht l 15 ri dn dn xung14, cho ti 0 tng cng sau 15 xung ck v ti xung ck th 16 mch s tng xo v 15 m xung tr li.

Hnh di y trnh by c 2 dng sng ca mch m ln v xung bn c thso snh chng thy r hn nguyn l ca s m ln v m xung.

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hnh 3.4 So snh dng sng m ln v m xung

Hy ni dy 4 FF T to ra mch m ln, mch m xung chia 16, c ng

ck tcng mc cao.

Thay FF T bng FF JK v thit k tng t

Thm mt bc na l cng vi tng y FF ta s thit k mch c th mln m xung u c.

Nhn thy mch m ln hay xung l do ni t ng ra Q ca tng trc ting vo ck ca tng sau do y s phi dng mt cng OR cho 2 ng vo.

Vic m ln xung c quyt nh bi mt ng iu khin chn ch lnhay xung. Cu trc ca mch s c thit k nh sau :

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Hnh 3.5 Mch m ln hay xung

IV. Sn phm trn hnh nh 3D

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Nhn xt ca gio vin:

..:

Do trnh v thi gian nghin cu tm hiu cn hn hp, nn bi bo co ca chng em cnnhiu thiu st. Chng em rt mong c s gp ca thy c v cc bn bi bi bo cot cht lng tt hn!Xin chn thnh cm n!

Thi Nguyn 12/2011

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