CD ghi h~i duqe RW ( Rewritcahle) baa gom cac lOp sau: • Lap nhan hi~u (kh6ng nhat thiet cdn den).
llillh 2-9: Did, gecmaJli tie'p diem
Di6t geemani tiep di~m (hinh 2-9a) gom m"t vo bang thuy tinh hay kim 1011-1, dUOng kinh khnang 3-9mm. hai d<iu co hai day dan ra. 0 dau ella m¢t day e6 gan lap tinh th~ gecmani 1 c6 Hnh tliln di¢n 10l:\i N, a dau day kia gan m¢t kim nhc;m 2, mili nhqn lam bang Indi. Lap ticp giap P-N duge tl:\0 ra trong qua trinh chc t~o bang each ph6ng mQt dong di~n xung qua diot. Lue d6 cae nguyen tt! lndi khucch tan vao kh6i gccman.i t~o thanh mQt lap ban dan lo~i P
(Gccmani co tan t~p chat Indi thu¢c nhem 3) va do d6 tiep gi3.p P-N duqe hinh thanh. 6 ben trai (hinh 2-9a) co YC to J(jp tier giap nay. Hlnh 2 9b la d~c
(uyen VOIl - Ampc ella di6t nay.
Di6t gccmani tiep xue m~l (hlnh 2-10) g()m tam gecmani I c6 pha mQl it ascn ho~c anlimoan de: co 11nh dan di¢n tt!. Trcn tam gccmani Ii!. lap Indi 2 n6i tai di¢n C\!C ra.
I (A)
0,5
- 400 - 200
u
0 ' (V)
Hinh 2-10: Dial gecmani liep mt;'1t
Khi chc t~o, nguoi ta d~t micng Indi I~n m<\tllap gecmani dii duge nung tai nhi¢t d¢ khuting 5000C (cao han nhi~t d¢ n6ng chay eua Indi). Lilc d6 Indi n6ng ehay va khucch tan vao kh6i gcemani tl:\0 thanh m¢t lap mong c6 tmh dan di~n 10l:li l~ Nho d6, lap tiep giap P-N duge t<;io thanh.
Hi~11 nay lo~i diot Gccmani tiep xuc m~t dang dugc san xuat nhiCu va Slr dl,mg trong ky thu~t ba.n dan c6ng sua't Ian. So vai di6t gecmani, di6t silie co
cae uu di~m sau:
I. Di¢n ap nguqc eho phcp Ian hO'n, tai 700-800V va hang nghln v6n, trong khi diot gcemani e6 di~n ap nguqc khoang 400V.
2. Nhi¢t d" l~m vi~c cao hm1, tai 125 - 150nC trong khi di6t gcemani lam Yi~c
a nhi¢t dQ 50 - 7Y'C. Neu chet~o d~c bi¢t, di6t silic co th61am vi~c a 30OUC. 55
3. M~L d9 dong di¢n cho phcp 16n han, t6i 60-80 A/cml
, t6i da co th~ t6i 200A/cm), trong khi di61 gcemani chi lam vi~c voi m~t d9 20-40A/cm1
, t6i da cfing chi t(1i JOOA/eml.
4. Dong di¢n ngu<Jc eua di6t silic nho hon eua di6t geemani toi vat l:1n. Nhuqe di6m eua di6t silie Iii. sl,It ap Hcn di61 Ion han so voi di6t gecmani. Sl,It ap b dWl silk Iii. 0,5 0,8V, con a (ti6t Geemani Iii. 0,3V.
4.2. Ml)t sa diat ban dan d<)e bi¢t
4.2.1. Diotan tip (dia'i Zene)
Di6t c)n ap ung dl,lng hi¢n tuqng Zene nen con gqi Iii. di6t Zene, dung tl~
6n djnh di¢n ap d.;i1 van Lai.
Hinh 2-1 ° la c1<;1-ng du(mg d.;te 1[nh Von-Ampe eua diot 6n ap.
Phan 1hu~n eua d~c lInh nay cGng giong nhu cae diot thong thuang. Phan nguqe eua d~e tfnh e6 khae. Neu tang di¢n ap nguqe, hie dau dong di¢n nguqe eGng e6 1ft s6 rat be nhu di61 klute.
100 max
Illnh 2-11: Kv hi¢u vel d(ic luye/l \ 'an - Ampe Cttel dial Zelle
Nllltng den m01 If! s6 I1hat dtnh eua Ull~ (di~m A) se xiiy fa <10L bien, dong di¢n nguqc tang dqt ngqL, con di¢n ap giiJ gan nhu khong d6i, dubng di,j.c Hnh gan nhu song song v6i tfl,le dong di¢n(do<;tn AB). D6 ehfnh Iii. elo<;tn 6n ap. d
cae diot thong thuang hi¢n tuqng danh thung xiiy fa sc lam hong tiep giap, do d6 di6t b~ hong. Sb di: di 6t Zenc klu)ng bt hong tiep giap khi bj danh thung ia khi ehc t'.1o nguai ta eta t1nh toan c16 ticp giap ehiu dU<Je dong di¢n ngU(1e khi chqc thung nha sir dl,lng 10'.1i ban dan voi muc t'.1P chat phu hqp. Cae diat Zene lhu(1ng lam bang silie la 10<;l-i v~t li¢t co suc ehtu nhi¢l elq t6t. Hlnh 2-11 Iii kf hicu eua dit:lt Zcne 1rcn sa d6.
Gi6i h~n 6n dinh di~n ap Iii. tll di)ng di~n ngu<Je be nhit Ioo,mlJl dcn lUn nha1 1 .. 1",,,, xac dtnh theo dieu ki¢n e(mg suit ti~u tan ello phep Pm"".
1 o d .,mm .