Thit kYu cu:Loi mch :OTL.Ng vo:Vi sai.Cng sut:60W.in p vo :776mV.Tr khng loa:4.Tr khng vo :100K.Bng thng:16Hz 20KHz.Mo phi tuyn :1%.CMRR :30dB. TNH TONTng ngun: 1.1> Bin tn hiu ra loa: Tn hiu vo ca mch khuych i c dng sin:. sin t V v Xem h thng l tuyn tnh th tn hiu ra trn ti: 00sinsinC L LCE L LI t I iV t V v+ + vi : ,L L I V l bin in p v dng ra trn ti.

: ,0 0 C CEI V l in p v dng in DC trn ti. Do tng cng sut lm vic ch AB nn dng tnh v in p tnh ri trn ti khng ng k .Do vy: t I it V vL LL Lsinsin Gi : ,Lhd LhdI V l in p hiu dng v dng in hiu dng trn ti.

2,2LLhdLLhdIIVV Khi cng sut trn ti :

) ( 475 , 549 , 21) ( 9 , 21 4 . 60 . 2 22.2 22ARVIV R P VVRVI R PLLLL L LLLLhdLhd L L 1.2> in p ngun cung cp: m bo v mt nng lng v trnh nhiu phi tuyn th in p ngun phi bng hai ln in p trn loa. Mc khc, v 2 1, Q Q lm vic ch AB nn chn h s s dng ngun l 0,8.Do vy: ) ( 75 , 548 , 09 , 21 . 28 , 02VVVLCC Ta chn ngun cung cp l : . 60V VCC 1.3> Cng sut ngun cung cp: - Dng cung cp trung bnh: LL L CCtbIt I t d t I I 00cos1. sin21 - Cng sut ngun cung cp:W) ( 56 . 104475 , 560 LCC CCIV P1.4> Hiu sut ca mch: % 38 , 5756 , 10460 CCLPP2> Tng khuych i cng sut: Tng khuych i cng sut c nhim v pht trn loa mt tn hiu m tng c xc nh theo yu cu thit kW 70 LP . Cc BJT lm vic mc in p cao, cc dng collector 2 1, Q Q rt ln. V vy, 2 1, Q Q phi c chn ph hp ng thi phi chn ngun, dng ngun khong c vt qu gi tr cho php ca BJT nhng cng phi ln m bo cng sut v hiu sut mch. trnhmo xuyn tm ng thi m bo hiu sut, ta chn 2 1, Q Q lm vic ch AB.V mch lm vic ch AB nn dng tnh collector nm trong khongmA 50 20 . y ta chn mA I I IQ Q QE E E502 1 . Dng nh qua 2 1, Q Ql: ) ( 525 , 5 475 . 5 10 . 5032 11A I I I IL E E EQ P P + + 2.1> Tnh chn : ,2 1 R R 2 1, R R c tc dng cn bng dng , n nh nhit nn phi c kch thc ln chu c cng sut ln.Dng tn hiu trn 2 1, R R l: t I i iL e e sin2 1 .Nu chn 2 1, R R ln th tn hao trn loa nhiu do phi chn sao cho tn hiu ra loa l ln nht. trnh tn tht tn hiu ra loa ta thng chn: ) ( 198 , 0525 , 5095 , 1095 , 1209 , 2120 201112 111 PERLRLRIVR RVVVVTa chn 2 , 02 1R R. Cng sut tiu hao trn 2 1, R R l:W) ( 997 , 24) 475 , 5 (2 , 02 21212 2121 2 1 LLhd R RIR I R P P Vy chn W 52 , 02 1 R R2.2> Tnh chn cp : ,2 1 Q QCng sut ngun cung cp : LCC TB CC CCIV I V P Cng sut loa: 2 221L L Lhd L LI R I R P Cng sut tiu tn ca 2 1, R R : 21 1212L R RI R P P Vy cng sut tiu tn ca hai BJT 2 1, Q Ql : 2122121L L LL CCR L CC ttI R I RI VP P P P Cng sut tiu tn ca mt BJT, chn hn BJT 1Q l:

21 2 / 1 /) (412 2L LL CC ttQ tt Q ttI R RI V PP P + Ta thy cng sut tiu tn ca BJT 1Qph thuc vo LItheo hm bc hai. tm cng sut tiu tn cc i ta ly o hm ca1 / Q ttP theo LIv cho bng 0. 0 ) (21211 / + L LCCLQ ttI R RVdIdPW I R RI VPAR RVIL LL CCQ ttLCCL71 , 21 ) 55 , 4 )( 2 , 0 4 (4114 , 3 . 255 , 4 . 60) (41255 , 4) 2 , 0 4 ( 14 , 360) (2 20 101 max/1 + + ++ Cng sut tiu tn tnh trn 1Q : W 5 , 1 05 , 0 .2602.1 / 1 / 1 / EQCCQ C Q CE Q DCIVI V PVy cng sut tiu tn cc i trn 1Q l: W 21 , 23 5 , 1 71 , 211 / 1 max/ 1 max/ + + Q DC Q tt Q ttP P PV 2 1, Q Q l cp BJT b ph nn ta chn 2 1, Q Q tha mn iu kin:

W 21 , 23 ) 3 2 ( ) 3 2 (60525 , 5max01 > > > tt CCC CEp E CP PV V VA I ITra cu s tay Transistor Nht Bn ta chn c 1943 2 : ; 5200 2 :2 1SA Q SC Q.Tn P(W) fC ToCEV(V)CI(A)2SC5200 150 30MHz 150 230 15 55/1602SA1943 150 30MHz 150 230 15 55/1602.3> Tnh chn : ,4 3 R R Trong tnh ton ta chn: 55min 2 1 Q Q Dng Base tnh ca :1Q mAIIQ EQQ BQ89 , 055 150h 1fe11 /1 /++Dng Base cc I ca :1QmAIIQ EpQ BQp67 , 9856525 , 5111 /1 / + 4 3, R R khng nh hng n dng ra ch xoay chiu th 4 3, R R phI tha mn iu kin:Mdc B Mac BZ R R Z1 4 3 1, >Da vo s tay tra cu Transistor Nht Bn ct b ph ta chn:940 2 : ; 2073 2 :4 3SA Q SC QT n P(W) f(MHz) C To) (V VCEo) ( A IC2SC2073 25 4 150 150 1,5 40/75/1402SA940 25 4 150 150 1,5 40/75/1403> Tnh tng li: tnh ton tng li ta chn 753 Q) ( 052 , 075 194 , 31) ( 44 , 175 117 , 109133 /333 /3mAIImAIIQQ EQQ BQQ Epp B++ ++ 3.1> Tnh chn : , , ,3 2 1 2D D D VRR trnh mo tn hiu xuyn tm ng thi n nh im lm vic cho cc cp BJT khuych i cng sut th cc t hp ny pah lm vic ch AB. V vy, ta dng2 3 2 1, , ,RV D D D to ra p ban u cho cc BJT khi c tn hiu vo th cc BJT khuych i cng sut dn ngay.Chn : , ,3 2 1D D Dl loi 1N4148 l loi diode thu tinh. 2 1, Q Qlm vic ch dng tnh 50mA th in p trn tip gip BE ca cc t hp BJT ch tnh l 0,6V.Ta c: ) ( 6 , 2 2 , 0 . 05 , 0 2 , 0 . 05 , 0 6 , 0 6 , 0 6 , 0 6 , 04 32 1 4 2 1 3 4 3V VV V V V V V VQ B BQ R Q R BE BE BE BE Q B B + + + + + + + + + + dng tnh7Qt thay i v trnh mo tn hiu ta chn ) ( 8 , 28 44 , 1 . 20 203 7mA I Ip B CQ v dng Diode Zenner n nh p phn cc cho tng li.Nh vy, ba diode3 2 1, , D D D v 1VR m bo cho3 1, Q Q v 4 2, Q Q lm vic ch AB, tc l V VQ B B6 , 24 3 ngay khi c tn hiu vo. Li dng tnh cht ghim p ca diode ( dng qua diode tng nhng p t ln diode hu nh khng i. Mun c nh vy ta chn sao cho im lm vic nm trong on tuyn tnh nht(on thng)). Lc ny: ) ( 78 , 2710 . 8 , 286 , 0 . 3 6 , 23374 31 CQD Q B BIV VVRChn 401VR.sau hiu chnh li.3.2> Tnh ton transistor8Q lm ngun dng:8Q to dng in n nh phn cc cho7Qv n nh im lm vic ca cho hai cp Dalington tng khuych i cng sut. Chnh ni tr ngun dng ch xoay chiu ln nn tng h s khuych i ca tng li, phi hp tr khng vi tr khng vo ln ca 2 cp Dalington lm nng cao hiu sut ca mch.- Dng collector qua8Q: mA I IQ CQ Q CQ 7 / 8 /- Chn 4D l 1N4148, chn 1Z l Zenner 3V.Chn dng qua hai diode l dng phn p cho8Q. V diode Zenner hot ng n nh dng l 20mA. Chn dng phn p mA Ipa20 . Dng phn p rt ln so vi dng Base ca8Q. Lc ny V VD7 , 0 . St p trn9R l: ) ( 3 , 56 3 7 , 0 604 9V V V V VZ D CC R ) ( 815 , 210 . 203 , 56399 KIVRpaRChn K R 39 .Tnh chn:2VR) ( 15510 . 206 , 0 3 7 , 038 /1 42 + +Q CQBE Z DIV V VVRChn 2VR200 sau hiu chnh.Do8Q hot ng ch A c dng lm ngun dng nn cng sut tiu tn ln nht ca n l cng sut tiu tn tnh.in p DC trn tip gip CE ca8Q l: W 513 , 0 10 . 20 . 69 , 25 .) ( 69 , 252 , 0 . 05 , 0 6 , 0 6 , 0 ) 6 , 0 3 7 , 0 (260238 8 / 8 /8 /1 1 / 3 / 2 8 / + Q C Q CE Q DCQ CER Q BE Q BE VRCCQ CEI V PV VV V V VVVVy ta chn 8Q tha cc iu kin sau: ' > > >W 513 , 069 , 25208 /8 /8Q DC CQ CE CEoQ C CP PV V VmA I IDa vo bng tra cu ta chn 8Q: 2SA1013Tn P(mW) f(MHz) C T0) (V VCE) ( A IC2SA1013 900 15 150 160 1 603.3> Tnh chn BJT thc7Q: Transistor 7Q lm nhim v nng cao tn hiu ln kch cho tng thc lm vic v o pha cho tng cng sut. 7Q c chn lm vic ch A. 7Q c ti ln nn h s khuych i ln. ta phi chn im lm vic ca 7Qsao cho khi khng c tn hiu vo in th vo cc E ca0 ,2 1 Q Q , lc ny st p trn ti 0.Tr khng ti ca 7Q:3 / 3 3 8 / 0 7 /) 1 ( //(Q t be Q C Q tZ r R Z + + vi ) ( 34 , 18 2 , 238 ). 75 1 (94 , 325. 75 ) 1 ( ) 1 (3 / 33 /3 3 / 3 3 + + + + + + K ZI VZ rQ tQ EQTQ t be Do : K ZQ t34 , 187 /v >> K RQ Co34 , 188 /V7Q c in tr ti ln nn d dng ri vo vng bo ho gy mo tn hiu, do cn phi mc hi tip m mt chiu ln xoay chiu n nh im lm vic. in tr11 10, R R lm nhim v hi tip m DC, ring10R cn lm nhim v hi tip m AC cho7Q. Do7Q lm vic ch A, ta c th chn trc in p tnh trn in tr hi tip mt chiu11 10, R R l 3V.Ta c: ' +V V VVVRRR RRR311 1011101110 trnh hi tip m qu nhiu lm gim h s khuych i ca7Q, ta chn 11 10R R > >V V VmA I IP PCC CEQ C CQ tt C6020W 454 , 07 max/7 max/ Theo sch tra cu 1000 transistor quc t ta chn :7Q2SC2383 c cc thng s sau:TnP(mW) f(MHz)C To) (V VCE) ( A IC2SC2383 900 20 150 160 1 60/3203.4 Tnh ton cc in tr 12R13R3VR: Vi 607 Q ta c dng tnh ca7Q l:

mAIIQQ CQQ BQ33 , 0602077 /7 / Tr khng vo ca tng thc: ) ) 1 ( //( ) // // (10 7 7 / 3 13 12 7 /R r VR R R ZQ Q be Q in + + vi ) ( 752025. 607 /7 7 / Q EQTQ Q beI Vr ) ( 3125 // ) // // ( ) 50 . 61 75 //( ) // // (3 13 12 3 13 12 7 / + VR R R VR R R ZQ in p ti cc B ca7Q: '2 /3 1337 /) (Z Z Q BVVR R VRV+vi '/ Z ZV: l in p lm vic ca diode Zenner. Theo cng thc tnh ton ca l thuyt ta c: ) ( 81 , 15 81 , 0 15'V V V VZ Z Z + + V C C T TV TVo o Z CZ81 , 0 ) 25 100 (10015 . 072 , 0) (1000 1 Mc khc p ti B ca7Q:) ( 6 , 3 3 6 , 011 10 7 / 7V V V VR R Q BE BQ + + Chn dng phn p cho7Qtho mnpaI 7 /10Q BQI. Ta chn mA I IQ BQ pa3 , 3 107 / ) ( 09 , 13 , 36 , 37 /13 KIVRpaQ B

KI V VVRpaQ B z z7 , 33 , 36 , 3 81 , 157 /'/3 Chn ' K VRK R51313 sau hiu chnh 3VR. ++ KI IV VRpa Z ZZ Z CC93 , 13 , 3 2015 602 /'2 /12 . chn K R 212 Tr khng vo ca tng thc: K ZQ in5 , 0 125 , 3 // ) 1 // 5 // 2 (7 / 3.5> H s khuych i ca tng thc:Theo cng thc ( ) ta c h s khuych i ca tng thc l:

1 , 35250 ) 60 1 ( 751843060) 1 (10 7 7 /7 /7+ + + + R rZKQ Q beQ tQ UlnTnh theo n v dB:dB dB KU51 ) 1 , 352 lg( 20 ) ( 4> Tnh tng khuych i vi sai: Do10 9, Q Ql cp BJT khuych i vi sai tn hiu u vo u tin nn tng ny quyt nh mc tp m cho mch. gim tp m ta chn10 9, Q Qlm vic ch A v c h s khuych i nh. mch lm vic n nh v7Qkhng nh hng nhiu n tng ny ta chn9 / Q CI 7 / Q BQI. Vi 7 / Q BQI0,33mA chn mA IQ C29 /) ( 84 , 17 16 , 42 60'4 / 14V V V VZ Z CC R Theo cng thc tnh ton ca l thuyt ta c: V V V VZ Z Z16 , 42 16 , 2 40' + + V T TV TVZ CZ16 , 2 ) 25 100 (10040 . 072 , 0) (1000 1 phi hp tr khng gia tng thc v tng khuych i vi sai ta chn: ) ( 27 / 17 16 K Z R RQ inchn K R R 217 16Nu b qua st p trn bin tr5VRth: 9 / 5 16 9 / 0'4 / 9 / 5 16 4 / ' 11 /9 / 16 4 / ' 11 /.Q CE VR Q C Z Z Q CE VR R Z Z Q CEQ C R Z Z Q CEV V R I V V V V V VV V V V Vi11 / 3 / ' 5 Q BE D Z Z VRV V V V + W 07 , 0 10 . 2 . 898 , 34898 , 34) ( 898 , 34 898 , 34 262 , 3 10 . 2 . 10 . 2 16 , 42262 , 3 6 , 0 7 , 0 162 , 3) ( 162 , 3 ) 25 100 (1003 . 072 , 03 ) (1003/ max maxmax/9 / 9 /3 3/50 13 /3 /' < + + + Q CQ CEQ CEQ CE Q CE Q CEVRZ Z CZZ ZI V PV VV V V VV VV T TV TV VDo cn chn 9Q v 10Q tha mn nhng iu kin sau:

' > > >V V VmA I IP PZ Z CEQ CQ CC C402 ). 5 3 ( ) 5 3 (W 14 , 0 24 / '9 /maxTra cu s tay linh kin 1000 transistor quc t ta chn 9Q v10Q nh sau:

Tn P(mW) f(MHz)C ToCEV(V) CI(mA)2SC1815 400 80 125 50 150 250Bin tr 4VRdng cn bng dng Emitor cho9Q v10Q do ta chn 4VRc gi tr nh. Chn 1004VRXt tng vi sai c mch nh hnh v: Vi 18 6'4 / 610 /R VR V VRVZ ZQ B+

V mch khuych i vi sai c thit k sao cho ch tnh hai nhnh cn bng nhau.

'15 6 1810 ///2R VR RVVCCQ B '15 6 1818 6//30 10R VR RR VR(1)Mc khc trong ch tn hiu: - Khi cha c hi tip m th tr khng vo ca tng vi sai l indZ- Khi c hi tip m in p ni tip thng qua4 7 15, , C VR Rth tr khng vo ca tng vi sai s tng ln g ln vi g l su hi tip. ind indfgZ Z vihtA A g01+ 0A: li vng h. htA: h s hi tip.Do , tng tr vo ca ton mch khi c hi tip l:6 18 6 18// // ) // ( VR R Z VR R Zindf in v ) // (6 18VR R Zindf>>V th6 18// VR Rquyt nh tr khng vo ca mch. Theo yu cu thit k th K Zin350nn chn K VR R 350 //6 18 (2)T (1) v (2) ta tnh c: ' K RK VRK R10040033 , 13315618Chn ' K RK VRK R10050015015618sau hiu chnh lI 6VR.5> Tnh transistor ngun dng 11Q: Chn5D: l 1N4148 v Diode Zenner3Zl 3V ng vi dng mA ID20 . Khi mA ID205 th V VD7 , 05 v V VZ Z33 /. 11 /11 / 3 / ' 55'Q EQ BE Z Z DIV V VVR +Vi ) ( 162 , 3 ) 25 100 (1003 . 072 , 03 ) (100'6 , 04 2 . 2 2 20 1/3 / / '11 /9 / 9 / 11 / 11 /V T TV TV VV VmA I I I IZ Z CZ Z Z ZQ BEQ C Q E Q C Q E + + Vy) ( 5 , 81510 . 46 , 0 162 , 3 7 , 035 +VRChn K VR 15 sau hiu chnh li.Chn dng phn p cho 11Ql dng lm vic ca diode5D l mA ID205 . KmAV V VRZ Z D D Z Z8 , 110 . 20262 , 3 7 , 0 402034 / ' 5 / 4 / '19 chn K R 219Ta c mA I I IQ C Q pa R24 4 20 . 29 / 11 / 14 + + ) ( 33 , 83310 . 2440 60 '3144 / '14 RZ Z CCI V VR Chn K R 114 Mc khc ta li c: 549 / 15 11 /2 2VRVRQ BE RCCQ CEVVV VVV VI ) ( 1 , 0 10 . 2 . 100 .21) . (212) ( 8 , 0 10 . 100 .25010 . 239 / 44331599 /15 9 / 15V I VRVV RIR I VQ CVRQQ CQ B R

) ( 838 , 25 ) 6 , 0 162 , 3 7 , 0 ( 1 , 0 6 , 0 8 , 026011 /V VQ CE + Vy cng sut tiu tn trn 11Ql:

W 1033 , 0 10 . 4 . 838 , 25 .311 / 11 / 11 / Q C Q CE Q ttI V PChn 11Q tha cc iu kin sau:

' > > >V V VmA I Im P PZ Z CEQ C CQ tt C408 2W 3 , 1034 / '11 /11 /Tra sch 1000 transistor quc t ta chn 11Q nh sau:Tn P(mW) f(MHz)C ToCEV(V) CI(mA)2SC1815 400 80 125 50 150 250Tnh ni tr ngun dng: ) ( 5 , 1 )100 10 . 5 , 1 85 // 10 . 2100250 1 ( 1010101 1) ( 5 , 1425250) ( 50) ( 3510 . 207 , 0)) // (1 (3 3511 / 05511 /1111 /11 /2033553 55 11 / 19511 11 / 11 / 0 + ++ + + ++ M RhrKI VrRIVRR R RVR r R RVRr RQ CQ oeceQ EQTQ bemA IZDDZ D DQ be DQ Q ce Q C6> Tnh h s khuych i v kim tra tr khng vo:6.1> H s khuych i:- H s khuych i in p tng thc:1 , 352 A- H s khuych i tng vi sai khi khng c hi tip: 10 4 10 / 7 157 / 1610. 2 //) // (Q Q beQ inQ dVR r VR RZ RA+ + - H s khuych i ton mch khi cha c hi tip:

A A Ad.0 - H s khuych i ton mch khi c hi tip m in p ni tip:Khi c hi tip: 7 157VR R VRvvAohtht+ su hi tip:ht htA A A g + 01 v10>>htA AH s khuych i ton mch:

ht htA A AAA1100+ Mt khc ta c: 96 , 19776 , 0 . 29 , 212 inLVVA ) ( 27 , 596 , 1810096 , 1896 , 191 11577 157 +KRVRAA VR R VRhtChn K VR 107sau hiu chnh li cho ph hp.01 , 12896 , 191. 12 , 2535 1 112 , 2535 ) 1 , 352 .( 2 , 72 , 7100 . 250225250 . 2 10 ). 10 // 100 (10 ). 2 // 2 (2500033 + + + + htddA A gA A AA6.2> Tr khng vo ca mch:- Tr khng vo tng vi sai:+ Khi cha hi tip: + + + + K ZVR R VR r ZindQ Q be ind259 , 31 3125910 ). 10 // 100 ( 100 . 250225. 250 . 2 ) // ( 237 15 4 10 10 /+ Khi c hi tip: M K gZ Zind indf4 4001 259 , 31 . 01 , 128- Tr khng vo ton mch:

K Z VR R Zindf in38 , 115 10 . 4 // ) 500 // 150 ( // ) // (36 186.3> H s khuych i ng pha:4311 / 01610 . 67 , 610 . 5 , 1 . 222 Q CCMRRK7> Tnh cc thng s cn li: 7.1> Tnh mch bo v: 7.1.1> Trng hp qu ti:Mch qu ti tc V Vin776 , 0 >lc V VL9 , 21 > .Xt trng hp qu ti ln nht lc 2 1, Q Q dn bo ha. VVVCCL302602 Dng nh qua ti: AR RVILCCLp14 , 74 2 , 03021++Cng sut loa: W 10224 . ) 14 , 7 () 2 (222' L LpLR IPCng sut ngun cung cp: W 4 , 13614 , 314 , 7 . 60.' Lp CCCCI VP Cng sut tiu tn trn 1R : W 55 , 24) 14 , 7 .( 2 , 04221 '1 LpRI RP Trng hp ngn mch: Xem nh loa b ly ra khi mch, lc ny 2 1, R Rl ti ca 2 1, Q Q . Trng hp xu nht l in p trn loa t ht trn 2 1, Q Q . Dng qua 2 1, R R : ) ( 5 , 1092 , 09 , 211'R11ARVIL Cng sut tiu tn trn 2 1, R R: W 5 , 5594) 5 , 109 .( 2 , 04221'1 '2'1 RR RI RP P Cng sut ngun cung cp: W 6 , 399314 , 35 , 109 . 60 .1 ' R CCCCI VP Cng sut tiu tn ca hai BJT: W 6 , 2874 5 , 559 . 2 6 , 3993 2 2'1' ' R CC ttP P PCng sut tiu tn trn mi BJT l: W 3 , 143726 , 2874'2 /'1 / Q tt Q ttP PTrng hp ny th hai BJT v hai in tr u b hng. Phi c mch bo v.7.1.3> Tnh mch bo v:Hot ng: bnh thng khi mch khuych I cng sut lm vic th 6 5, Q Q tt. Khng nh hng n hot ng ca mch. Khi xy ra ngn mch dng qua 2 1, Q Q ln s nh thng BJT cng sut v in tr 2 1, R R . V vy khi dng qua hai BJT ln s kch thch mch bo v hot ng. Mch ny s ht dng lm cho dng qua hai BJT v in tr 2 1, R Rnh m bo cho hai BJT lm vic an ton.- Dng nh qua 2 1, R R : A Ip E525 , 51

- Chn dng mch bo v hot ng l:A I p E 7 1'- St p trn 1R:V R I Vp E R4 , 1 2 , 0 . 71'1'1 - Chn dng tnh mA I IQ C Q C16 / 5 / - Ta c V V V V V VR Q BE Q BE Q CE Q CE6 , 2 4 , 1 6 , 0 6 , 0'1 1 / 3 / 6 / 5 / + + + + - Cng sut tiu tn trn6 5, Q Q l: W 6 , 2 1 . 6 , 2/ / 6 / 5 /m I V P PQ C Q CE Q tt Q tt Chn6 5, Q Q tha nhng iu kin sau: ' > > >W 6 , 2 ) 3 2 ( ) 3 2 (2 , 5 21///m P PmV V VmA I IQ ttQ CE CEQ C CDa vo sch 1000 transistor quc t chn:Tn P(mW) f(MHz)C To) (V VCE) (mA IC2SC1815 400 80 125 50 150 2502SC1015 400 80 125 50 150 2507.1.4> Tnh 8 7 6 5, , , R R R R:Dng tnh cc B ca5Q: AIIQQ CQ B2250155 /5 / Dng qua7 5, R R:5 / 515 , 0Q B pa RI mA I I >> Khi mch hot ng bnh thng th6 5, Q Q tt nn V VQ BE4 , 0/v V R I VA I IR Rp R R1 , 1 2 , 0 . 525 , 5525 , 51 max 1 max 11 max 1

) ( 66 , 210 . 15 , 04 , 03 , 715 , 01 , 1375 /7517 5 +KIVRKIVR RRQ BERR Chn K R 5 , 27 K R 8 , 4 5 , 2 3 , 75 chn K R 557.2> Tnh cc t:- Tnh t 1C :Ta chn t 1C sao cho tng s thp nht th st p trn t rt nh so vi st p trn loa khng nh hng n tn hiu ra trn loa. Ta chn L CR X1011 F CRC fXL C248804 , 0 . 16 . 14 , 3 . 214 , 0 4 .1011011 . 211min1 chn V F C 50 / 250001 - Tnh t5C:5Cl t lin lac ng vo nn st p trn t khng nh hng n tn hiu vo v cht lng ca mch ta chn tC sao cho in CZ X1015 FZ fCin99 , 010 . 100 . 16 . 14 , 3 . 210. . 2103min5 Chn t V F C 50 / 15 - Tnh t 2C : T 2Cl t lin lc gia tng vo vi sai v tng li nn chn t 2Csao cho st p trn t khng nh hng n tn hiu vo tng li. Ta chn t 2Csao cho 7 / 2101Q in CZ X

FZ fCQ in76 , 4910 . 2 . 16 . 14 , 3 . 210. . 21037 / min2 ChnV F C 50 / 562 - Tnh t 4C :T 4Ckt hp vi7 15,VR Rto thnh mch hi tip m n nh thng s ca mch.Chn t 4Csao cho t s hi tip tn hiu ch ph thuc vo7 15,VR R v st p xoay chiu trn 4C nh hn7VRrt nhiu. Chn FVR fCVR XC9 , 910 . 10 . 16 . 14 , 3 . 210. . 21010137 min47 4 ChnF C 104 - Tnh t6C:T6Ccng vi 14R to thnh mch lc thng thp lc nhiu (hi bc cao) t ngun trnh hi tip v to thnh dao ng t kch. FR fCR XC52 , 9910 . 1 . 16 . 14 , 3 . 210. . 210101314 min614 6 Chn V F C 70 / 1006 - Tnh t3C: FR fCR XC2 , 995100 . 16 . 14 , 3 . 210. . 21010111 min311 3 Chn V F C 50 / 10003 7.3> Tnh mch lc Zobel ) , (20 7 R C: Cu to ca loa gm mt cun cm v mt in tr cL j R ZL L + . Nh vy, tr khng loa ph thuc vo tn s. Khi tn s cao tr khng loa cng ln dn n mo tn hiu.Mch lc Zobel l mch n nh tr khng loa khng i tn s cao.C mc ni tip viR v tt c mc song song vi ti LR . tn s cao t ngn mch gim ti ng ra tc l C LX X , LR khng i. Ta c: ) //( )1( L j Rc jR ZL td+ + khng ph thuc vo tn s th 420 LR R v chn t 7Csao cho L CR X1017

FR fCL9 , 194 . 10 . 20 . 14 , 3 . 210. 2103. max7 Vi KHz f 20max.Chn V F C 50 / 257 7.4> Kim tra mo phi tuyn:Trong mch hu ht cc linh kin lm vic ch A ch c cp 2 1, Q Qlm vic ch AB nn mo phi tuyn ton mch ph thuc ch yu 2 1, Q Q .Gi s tn hiu vo l hnh sin v V Vin776 , 0 . Lc ny in p t ln tip gip BE ca 1Q :t V V t VBEm Q BE BE sin ) (1 1+ Trong : V V V VV VQ BE BEp BEmQ BE4 , 0 6 , 0 16 , 011 Gi 0 CI l dng r ca 2 1, Q Q .TBEmTBEQTBEVt VVVCVVC Ce e I e I I) sin(0 0 Khai trin TBEmVt Ve y) sin( theo chuI Taylor:..... ) ( sin21sin 122+

,_

+ + tVVtVVyTBEmTBEm Mo phi tuyn ch yu do hi bc cao gy ra. Loi hi bc cao v bin i 2) 2 cos( 1) ( sin2ttta c: ) 2 cos(41) sin(411222tVVtVVVVyTBEmTBEmTBEm

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+ + Theo nh ngha mo phi tuyn: mniimII122 Trong : mI1: thnh phn dng c bn. imI: bin hi.Loi b cc hi bc cao ta c:

TBEmTBEmTBEmmmVVVVVVII442212 Khi cha c hi tip: 84 , 3026 , 0 . 44 , 04 TBEmVV Khi c hi tip: g R gL m) 1 ('+ g: su hi tip: 01 , 128 g :mg h dn.mVmAVIrgTQ EQ beQm265011 /1 % 1 % 33 , 001 , 128 ) 4 .25501 (84 , 3) 1 (' < ++g R gL m