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- 2: Tranzitor
s: V~t li¢u c h€ t
- • Na.rn dU~1C cac thOng s6 c ua tranzitor (tra trung s6 tay tra cuu).
• Bi~t c ach do ki~rn tra tranzitor
Co th~ tharn khao cach do sau d ay
:;.: Ki~rn tra tranzitor thl!c ~h~t la t a ki~rn tra cac ti~p giap P-N cua tranzi-
tor. Ta co th~ coi s o d6 tuong dUC1I1g c ua tranzitor (Hinh 2 - 23) n hu sau d~ thl!c
hi~n do kiern tra:
~ I
- ban diln c 6 l iel di¢n Ihay d6i duoi lAc d~ng c ua di¢n I ntang t hang g6c voi lop
ban diln d6. T hay d 6i c uang d ¢ t ntang so I~m t hay d 6i d i¢n diin cUa l op ban
diin va do d6 l am t hay d 6i dong di¢n d i qua. di¢n I ntang i1 d ay lam nhi¢m vu
di~u khi~n dong di¢n. Hay n6l each khac tranzito t wang iil m¢t di¢n tra ban
diln dU
- I P
j
D
D
s N G
O-~
I I
I "P
s
G
b)
va ky hi¢u t ranzitor truang
I-llnh 2-2-1. e,i'u tflO
* Call tgo va kf hi¢u quy uac (Hinh 2-24)
Call t~o e lla l ranzitor n ay g 6m m ¢t t am ban d an lo~i P, t a k huech tan vila
d 6 h ai l op ban d an lo~i N v~ h ai phla k hae n hau (H'mh 2-24a). H ai l op b an d an
lo:;ti N n ay n oi v ai n hau t
- the giiii thieh d~e tuy€n VOn - AmI'" khao sat khi UCFeonst (HInh 2-25)
Th e 6
~n
+ K hi c hua c ung c ap di¢n a p ngoiH, n ghia HI. Uos=D vii Uso=O, hie oily
cGng hinh thiinh l op n ghco n hu t iep xuc P-N khi khOng c6 di~n a p p han q rc
d~t vao, dQ day e ua l ap n gheo kh6ng d 6i d qc t hea c hieu d ai e ua k~nh.
d~t di~na p va~, c hi x et v ai mQt d uang d~c trl1ng (U'ng vOi m ¢t gia
+ Khi t a
tr~ e ua U.S (UGs=const ). Uc,s se d am bao p han cl[c n guqc ello ti~p x uc P -N, k hi
c6 U JS r6i nhl1ng UDS veln c hua co t hl d ong IDs' van ha.ng 0, va he day e ua 16p
nghco se day han trong l ruong h dily t hay d di, d ing di ve p hia cl!c mling
t hllop n gheo c ang day len, sa eli n hu Y~y VI di¢n a p p han cl,Tc nguqc d .ng y~
phia mling d..ng IOn. N 6i e ach khac, d..ng v~ p hia q rc m ang t hi k enh c ang bi
h~p. Tiep t1~c t ang UDS Wn nfra d¢ r¢ng c ua k enh n gay d ing t hu h~p c ho d en k hi
a
UDS = U~, t hi h ai lOp n ghco t ren va duoi ch~p vao n hau di~m trimg voi cl!c
mang, ta gqi la di6m cat k enh k y hi¢u la P. Di¢n a p UDS ling voi di~m P n ay gqi
cat.
lit di~n tip
Tiep tl;lc t ang UDS l en nfra t hi di~m P se d ich d an v~ p hia cl!c n gu6n, n eu dq
dai c ua k enh dAn la L , 1 g qi l a d ¢ d ai k~nh c at, tlie la k hi UDS tlIng len thi d¢
dai k~nh c at I se tAng va dong di~n ch
- I
+ • I MN
N
2
+1 - o U MN
d)
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f)
Hinh 2-25. M 6 fa S~( hillll tlulnlz lap di¢n tfch khong g ian \'(1 d¢c tuye'n
Von - Ampe luong Ung
7
- * C ae dijc tinll c d b an:
~ D~ctrung tInh ca ban ella IFET:
+ D¢ dan ella kenh.
+ Di~n ap danh thung.
+ Di~n tn1 vao.
+ Di~n tra philn bo.
+ A nh huang ella nhi¢t d¢ va SIf dich chuy~n clla h~t dan di¢n.
~ D~c trLIng d¢ng c o ban ella IFET: Tan so cat va nhieu
Nhu v~y muon tranzito lam vi¢c duqc thi Hln s o lam v i¢efnh6 h an tan so
cat f·., ( JFET kenh n C6tio' Ian han/o~, I FET kenh p, de tranzito I~m vi¢e duqc
a litn s 6 c ao thi ta phai giam L tuc giam chieu diIi clla kenh)
DQ nhieu ella dong do elfc d ra G va nhi¢t sinh ra trong kenh dan.
2.2.2. Tranzito t ruimg k im 1000i - oxyt - b6n ddn ( MOSFET) k enh c am u ng
* ccru tqo va k i hi¢lI. (Iu'nh 2~26)
- Cau t~o: Gam 3 chat d n ghep If).i vai nhau I;), kim lo~i. o xyt vii ban dan.
Clfe d ra cach di¢n vai kenh bang m¢t lap di¢n m6i Si02 nen gqi III tranzito
truang c6 clfc cl'ra c aeh Iy IGFET.
O"ing ngh~ t~o MOSFET lit tren m(it dO ban dan Io~i p khuy€ch tan vito d o
hai l ap ban dan khac lo~i nong d ¢lan n+, m¢t lap la clfc nguon va m¢t lap la
clfC mang, sau d o phll l ap di¢n moi Si02 len tren m~t d e ban dan p-, tren lap
di¢n m6i mOl phu a khoang giUa hai l ap khueeh tan n ang dt) Ian n+ l~i phu
tiep m¢t 16p kim lo~i, JOp kim lo~i nay dung lam elle dra, s au do ta noi day
dan ra bang cac day kim Io~i ta se co 3 clfc G, D, S cung giong n hu JFET. V~y
ta c6 tranzito twang kim lo~i - oxyt - ban dan kenh n. ky hi¢u MOSFET kenh
n. Tuong til ta c ung co tranzito truang kim lo~i - oxyt ~ M.n dan kenh p.
ph an biet hai Io~i MOSFET kenh n va MOSFET kenh p c&n Iuu y:
D~
Neu d e Ia chat ban dan co ndng de) thap Io~i p (p-) thi MOSFET lit M OS-
FET kenh n. con neu lit lo"i n- thi MOSFET lit MOSFET kenh p. Vi d eban d an
co nang d¢ thflP nen di~n tro cua n6 100 va d e duqc cach di~n vai cac clfc D,S
va kenh. MOSFET ca ban khac vai JFET Hl cac h~t dan di¢n nam 6 vung sal
be mijJ ban dan va nong d¢ cua d .c h~t dan nay phV thuQc vuo di~n twang do
a
di¢n
- G
h
L.
o Si-P .
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CDU I~C c,;a m
nguon tai.lieu . vn
