{"id":2375,"date":"2018-07-11T08:55:27","date_gmt":"2018-07-11T08:55:27","guid":{"rendered":"https:\/\/hocvienit.vn\/?p=2375"},"modified":"2025-03-14T15:15:27","modified_gmt":"2025-03-14T08:15:27","slug":"tranzito-luong-cuc-transistor-bipolar","status":"publish","type":"post","link":"https:\/\/hocvienit.vn\/?p=2375","title":{"rendered":"Tranzito l\u01b0\u1ee1ng c\u1ef1c (Transistor Bipolar)"},"content":{"rendered":"

N\u1ebfu tr\u00ean c\u00f9ng m\u1ed9t \u0111\u1ebf b\u00e1n d\u1eabn ng\u01b0\u1eddi ta t\u1ea1o ra hai ti\u1ebfp gi\u00e1p P-N \u1edf g\u1ea7n nhau, d\u1ef1a tr\u00ean \u0111\u1eb7c t\u00ednh d\u1eabn \u0111i\u1ec7n c\u1ee7a m\u1ed7i ti\u1ebfp gi\u00e1p v\u00e0 t\u00e1c d\u1ee5ng t\u01b0\u01a1ng h\u1ed7 gi\u1eefa ch\u00fang s\u1ebd l\u00e0m cho d\u1ee5ng c\u1ee5 n\u00e0y c\u00f3 kh\u1ea3 n\u0103ng khu\u1ebfch\u00a0\u0111\u1ea1i \u0111\u01b0\u1ee3c nh\u1eefng t\u00edn hi\u1ec7u \u0111i\u1ec7n.<\/span><\/p>\n

\"Transistor
Transistor Bipolar<\/figcaption><\/figure>\n

1. C\u1ea5u t\u1ea1o<\/strong><\/b><\/span><\/h2>\n

G\u1ed3m 3 l\u1edbp b\u00e1n d\u1eabn gh\u00e9p li\u00ean ti\u1ebfp nhau, hai l\u1edbp ngo\u00e0i c\u00f9ng c\u00f3 t\u00ednh d\u1eabn \u0111i\u1ec7n c\u00f9ng lo\u1ea1i, l\u1edbp \u1edf gi\u1eefa c\u00f3 t\u00ednh d\u1eabn \u0111i\u1ec7n kh\u00e1c v\u1edbi hai l\u1edbp ngo\u00e0i. Tu\u1ef3 theo c\u00e1ch s\u1eafp x\u1ebfp c\u00e1c kh\u1ed1i b\u00e1n d\u1eabn m\u00e0 ta c\u00f3 Tranzito thu\u1eadn p-n-p (h\u00ecnh a) v\u00e0 Tranzito ng\u01b0\u1ee3c n-p-n (h\u00ecnh b) \u0111\u01b0\u1ee3c ch\u1ec9 ra tr\u00ean h\u00ecnh v\u1ebd.<\/span><\/p>\n

\"C\u1ea5u
C\u1ea5u t\u1ea1o Transistor Bipolar<\/figcaption><\/figure>\n

– L\u1edbp (mi\u1ec1n) b\u00e1n d\u1eabn th\u1ee9 nh\u1ea5t g\u1ecdi l\u00e0 l\u1edbp ph\u00e1t (Emit\u01a1), c\u00f3 \u0111\u1eb7c \u0111i\u1ec3m l\u00e0 n\u1ed3ng \u0111\u1ed9 t\u1ea1p ch\u1ea5t l\u1edbn nh\u1ea5t, \u0111i\u1ec7n c\u1ef1c n\u1ed1i v\u1edbi n\u00f3 g\u1ecdi l\u00e0 c\u1ef1c ph\u00e1t E.<\/span><\/p>\n

– L\u1edbp th\u1ee9 hai g\u1ecdi l\u00e0 l\u1edbp g\u1ed1c (Baz\u01a1), c\u00f3 k\u00edch th\u01b0\u1edbc r\u1ea5t m\u1ecfng v\u00e0 n\u1ed3ng \u0111\u1ed9 t\u1ea1p ch\u1ea5t \u00edt nh\u1ea5t, \u0111i\u1ec7n c\u1ef1c n\u1ed1i v\u1edbi n\u00f3 g\u1ecdi l\u00e0 c\u1ef1c g\u1ed1c B.<\/span><\/p>\n

– L\u1edbp th\u1ee9 ba c\u00f3 n\u1ed3ng \u0111\u1ed9 t\u1ea1p ch\u1ea5t trung b\u00ecnh g\u1ecdi l\u00e0 l\u1edbp g\u00f3p (C\u00f4lect\u01a1), \u0111i\u1ec7n c\u1ef1c n\u1ed1i v\u1edbi n\u00f3 g\u1ecdi l\u00e0 c\u1ef1c g\u00f3p C.<\/span><\/p>\n

– Ti\u1ebfp gi\u00e1p gi\u1eefa l\u1edbp ph\u00e1t v\u1edbi l\u1edbp g\u1ed1c g\u1ecdi l\u00e0 ti\u1ebfp gi\u00e1p ph\u00e1t JE<\/span><\/p>\n

– Ti\u1ebfp gi\u00e1p gi\u1eefa l\u1edbp g\u1ed1c v\u1edbi l\u1edbp g\u00f3p g\u1ecdi l\u00e0 ti\u1ebfp gi\u00e1p g\u00f3p JC<\/span><\/p>\n

– Chi\u1ec1u m\u0169i t\u00ean trong k\u00fd hi\u1ec7u c\u1ee7a Tranzito bao gi\u1edd c\u0169ng l\u00e0 chi\u1ec1u c\u1ee7a \u0111i\u1ec7n \u00e1p ph\u00e2n c\u1ef1c thu\u1eadn cho ti\u1ebfp gi\u00e1p ph\u00e1t JE (c\u00f3 chi\u1ec1u t\u1eeb b\u00e1n d\u1eabn P sang b\u00e1n d\u1eabn N).<\/span><\/p>\n

2. Nguy\u00ean l\u00fd l\u00e0m vi\u1ec7c<\/strong><\/b><\/span><\/h2>\n

\u0110\u1ec3 cho Tranzito c\u00f3 th\u1ec3 l\u00e0m vi\u1ec7c \u1edf ch\u1ebf \u0111\u1ed9 khu\u1ebfch \u0111\u1ea1i t\u00edn hi\u1ec7u \u0111i\u1ec7n, ng\u01b0\u1eddi ta ph\u1ea3i \u0111\u01b0a \u0111i\u1ec7n \u00e1p m\u1ed9t chi\u1ec1u t\u1edbi c\u00e1c \u0111i\u1ec7n c\u1ef1c c\u1ee7a n\u00f3 g\u1ecdi l\u00e0 ph\u00e2n c\u1ef1c cho tranzito, sao cho ti\u1ebfp gi\u00e1p JE ph\u00e2n c\u1ef1c thu\u1eadn v\u00e0 ti\u1ebfp gi\u00e1p JC ph\u00e2n c\u1ef1c ng\u01b0\u1ee3c nh\u01b0 h\u00ecnh v\u1ebd.<\/span><\/p>\n

\"Nguy\u00ean
Nguy\u00ean l\u00fd ho\u1ea1t \u0111\u1ed9ng transistor<\/figcaption><\/figure>\n

Gi\u1ea3 s\u1eed ta x\u00e9t tranzito pnp nh\u01b0 h\u00ecnh v\u1ebd Do ti\u1ebfp gi\u00e1p JE \u0111\u01b0\u1ee3c ph\u00e2n c\u1ef1c thu\u1eadn b\u1eb1ng ngu\u1ed3n UEB, \u0111i\u1ec7n tr\u01b0\u1eddng EEB n\u00e0y c\u00f3 t\u00e1c d\u1ee5ng gia t\u1ed1c c\u00e1c h\u1ea1t d\u1eabn \u0111i\u1ec7n \u0111a s\u1ed1 (l\u1ed7 \u00a0tr\u1ed1ng) \u00a0t\u1eeb \u00a0v\u00f9ng \u00a0ph\u00e1t \u00a0qua \u00a0JE \u0111\u1ebfn v\u00f9ng g\u1ed1c t\u1ea1o th\u00e0nh d\u00f2ng <\/span>\u0111i\u1ec7n c\u1ef1c ph\u00e1t IE. Do n\u1ed3ng \u0111\u1ed9 c\u00e1c l\u1ed7 tr\u1ed1ng \u1edf v\u00f9ng ph\u00e1t l\u1edbn n\u00ean d\u00f2ng \u0111i\u1ec7n c\u1ef1c ph\u00e1t IE c\u00f3 gi\u00e1 tr\u1ecb l\u1edbn.<\/span><\/p>\n

Khi \u0111\u1ebfn v\u00f9ng g\u1ed1c, m\u1ed9t ph\u1ea7n nh\u1ecf l\u1ed7 tr\u1ed1ng s\u1ebd t\u00e1i h\u1ee3p v\u1edbi c\u00e1c \u0111i\u1ec7n t\u1eed \u0111\u1ebfn t\u1eeb c\u1ef1c \u00e2m c\u1ee7a ngu\u1ed3n UEB t\u1ea1o th\u00e0nh d\u00f2ng \u0111i\u1ec7n c\u1ef1c g\u1ed1c IB. Do v\u00f9ng g\u1ed1c c\u00f3 b\u1ec1 d\u00e0y m\u1ecfng v\u00e0 n\u1ed3ng \u0111\u1ed9 c\u00e1c h\u1ea1t d\u1eabn \u0111i\u1ec7n t\u1eed r\u1ea5t \u00edt n\u00ean d\u00f2ng \u0111i\u1ec7n c\u1ef1c g\u1ed1c IB r\u1ea5t nh\u1ecf. Ph\u1ea7n l\u1edbn c\u00e1c l\u1ed7 tr\u1ed1ng c\u00f2n l\u1ea1i khuy\u1ebfch t\u00e1n qua v\u00f9ng g\u1ed1c v\u00e0 di chuy\u1ec3n \u0111\u1ebfn ti\u1ebfp gi\u00e1p g\u00f3p JC. T\u1ea1i ti\u1ebfp gi\u00e1p g\u00f3p, \u0111i\u1ec7n tr\u01b0\u1eddng UCB thu\u1eadn chi\u1ec1u v\u1edbi c\u00e1c h\u1ea1t n\u00e0y n\u00ean s\u1ebd cu\u1ed1n ch\u00fang qua ti\u1ebfp gi\u00e1p JC sang l\u1edbp g\u00f3p \u0111\u1ec3 t\u1ea1o th\u00e0nh d\u00f2ng \u0111i\u1ec7n c\u1ef1c g\u00f3p IC.<\/span><\/p>\n

Th\u1ef1c t\u1ebf, v\u00ec ti\u1ebfp gi\u00e1p JC ph\u00e2n c\u1ef1c ng\u01b0\u1ee3c n\u00ean tr\u00ean n\u00f3 v\u1eabn t\u1ed3n t\u1ea1i m\u1ed9t d\u00f2ng \u0111i\u1ec7n ng\u01b0\u1ee3c c\u00f3 tr\u1ecb s\u1ed1 nh\u1ecf (gi\u1ed1ng nh\u01b0 d\u00f2ng \u0111i\u1ec7n ng\u01b0\u1ee3c c\u1ee7a \u0111i\u1ed1t) ICB0, do m\u1eadt \u0111\u1ed9 c\u00e1c h\u1ea1t d\u1eabn thi\u1ec3u s\u1ed1 nh\u1ecf n\u00ean d\u00f2ng ICB0 c\u00f3 tr\u1ecb s\u1ed1 nh\u1ecf, ta c\u00f3 th\u1ec3 b\u1ecf qua.<\/span><\/p>\n

Khi \u0111\u00f3, ta c\u00f3 bi\u1ec3u th\u1ee9c d\u00f2ng \u0111i\u1ec7n trong tranzito l\u00e0:\u00a0<\/span><\/p>\n

IE = IB + IC. Do IB<<IE, IB<<IC n\u00ean IE \u00bb IC<\/span><\/strong><\/p>\n

\u0110\u1ec3 \u0111\u00e1nh gi\u00e1 m\u1ee9c \u0111\u1ed9 hao h\u1ee5t c\u1ee7a d\u00f2ng \u0111i\u1ec7n c\u1ef1c ph\u00e1t t\u1ea1i v\u00f9ng c\u1ef1c g\u1ed1c, ng\u01b0\u1eddi ta \u0111\u01b0a ra kh\u00e1i ni\u1ec7m g\u1ecdi l\u00e0 h\u1ec7 s\u1ed1 truy\u1ec1n \u0111\u1ea1t d\u00f2ng \u0111i\u1ec7n a: <\/span>a= IC\/IE, a\u00ae1 c\u00e0ng t\u1ed1t. (1)<\/span><\/p>\n

\u0110\u1ec3 \u0111\u00e1nh gi\u00e1 t\u00e1c d\u1ee5ng \u0111i\u1ec1u khi\u1ec3n c\u1ee7a d\u00f2ng \u0111i\u1ec7n c\u1ef1c g\u1ed1c t\u1edbi d\u00f2ng \u0111i\u1ec7n c\u1ef1c g\u00f3p ng\u01b0\u1eddi ta \u0111\u01b0a ra h\u1ec7 s\u1ed1 khu\u1ebfch \u0111\u1ea1i d\u00f2ng \u0111i\u1ec7n b: b=IC \/IB. (2)<\/span><\/p>\n

Th\u01b0\u1eddng b = v\u00e0i ch\u1ee5c ho\u1eb7c v\u00e0i tr\u0103m l\u1ea7n, t\u1eeb(1) v\u00e0 (2) ta c\u00f3 quan h\u1ec7: a= b\/1+b<\/span><\/p>\n

\u0110\u1ed1i v\u1edbi Tranzito ng\u01b0\u1ee3c P-N-P, nguy\u00ean l\u00fd l\u00e0m vi\u1ec7c c\u0169ng t\u01b0\u01a1ng t\u1ef1 nh\u01b0 tranzito thu\u1eadn, ch\u1ec9 kh\u00e1c l\u00e0 \u1edf tranzito ng\u01b0\u1ee3c ph\u1ea7n t\u1eed mang \u0111i\u1ec7n \u0111a s\u1ed1 \u1edf c\u1ef1c ph\u00e1t l\u00e0 \u0111i\u1ec7n t\u1eed, \u0111\u1ed3ng th\u1eddi \u0111\u1ec3 cho s\u01a1 \u0111\u1ed3 ho\u1ea1t \u0111\u1ed9ng ta ph\u1ea3i \u0111\u1ed5i l\u1ea1i c\u1ef1c t\u00ednh c\u1ee7a c\u00e1c ngu\u1ed3n \u0111i\u1ec7n c\u0169ng nh\u01b0 \u0111\u1ed5i l\u1ea1i chi\u1ec1u c\u1ee7a c\u00e1c d\u00f2ng \u0111i\u1ec7n IE, IB, IC.<\/span><\/p>\n

3.C\u00e1c c\u00e1ch m\u1eafc Tranzito \u1edf ch\u1ebf \u0111\u1ed9 khu\u1ebfch \u0111\u1ea1i<\/strong><\/b><\/span><\/h2>\n

Khi s\u1eed d\u1ee5ng v\u1ec1 nguy\u00ean t\u1eafc c\u00f3 l\u1ea5y hai trong s\u1ed1 ba c\u1ef1c c\u1ee7a tranzito l\u00e0m \u0111\u1ea7u v\u00e0o, c\u1ef1c th\u1ee9 ba c\u00f2n l\u1ea1i c\u00f9ng v\u1edbi m\u1ed9t c\u1ef1c \u0111\u1ea7u v\u00e0o l\u00e0m \u0111\u1ea7u ra. Nh\u01b0 v\u1eady c\u00f3 t\u1ea5t c\u1ea3 s\u00e1u c\u00e1ch m\u1eafc m\u1ea1ch kh\u00e1c nhau. Nh\u01b0ng d\u00f9 m\u1eafc nh\u01b0 th\u1ebf n\u00e0o c\u0169ng c\u1ea7n c\u00f3 m\u1ed9t c\u1ef1c chung cho c\u1ea3 \u0111\u1ea7u v\u00e0o v\u00e0 \u0111\u1ea7u ra. Trong s\u1ed1 s\u00e1u c\u00e1ch m\u1eafc \u0111\u00f3 th\u00ec ch\u1ec9 c\u00f3 ba c\u00e1ch m\u1eafc l\u00e0 tranzito c\u00f3 th\u1ec3 khu\u1ebfch \u0111\u1ea1i \u0111\u01b0\u1ee3c c\u00f4ng su\u1ea5t, \u0111\u00f3 l\u00e0 c\u00e1ch m\u1eafc chung Emit\u01a1 (EC), chung Baz\u01a1 (BC) v\u00e0 chung Colect\u01a1 (CC). Ba c\u00e1ch m\u1eafc c\u00f2n l\u1ea1i kh\u00f4ng c\u00f3 \u1ee9ng d\u1ee5ng trong th\u1ef1c t\u1ebf.<\/span><\/p>\n

\"\"T\u1eeb c\u00e1ch m\u1eafc \u0111\u01b0\u1ee3c d\u00f9ng trong th\u1ef1c t\u1ebf c\u1ee7a tranzito, v\u1ec1 m\u1eb7t s\u01a1 \u0111\u1ed3 c\u00f3 th\u1ec3 coi tranzito l\u00e0 m\u1ed9t m\u1ea1ng 4 c\u1ef1c g\u1ea7n tuy\u1ebfn t\u00ednh c\u00f3 hai \u0111\u1ea7u v\u00e0o v\u00e0 hai \u0111\u1ea7u ra.<\/span><\/p>\n

C\u00f3 th\u1ec3 vi\u1ebft ra 6 c\u1eb7p ph\u01b0\u01a1ng tr\u00ecnh m\u00f4 t\u1ea3 quan h\u1ec7 gi\u1eefa \u0111\u1ea7u v\u00e0o v\u00e0 \u0111\u1ea7u ra c\u1ee7a m\u1ea1ng 4 c\u1ef1c trong \u0111\u00f3 d\u00f2ng \u0111i\u1ec7n v\u00e0 \u0111i\u1ec7n \u00e1p l\u00e0 nh\u1eefng bi\u1ebfn s\u1ed1 \u0111\u1ed9c l\u1eadp. Nh\u01b0ng trong th\u1ef1c t\u1ebf t\u00ednh to\u00e1n th\u01b0\u1eddng d\u00f9ng nh\u1ea5t l\u00e0 3 c\u1eb7p ph\u01b0\u01a1ng tr\u00ecnh tuy\u1ebfn t\u00ednh sau:<\/span><\/p>\n

C\u1eb7p ph\u01b0\u01a1ng tr\u00ecnh tr\u1edf kh\u00e1ng c\u00f3 \u0111\u01b0\u1ee3c khi coi c\u00e1c \u0111i\u1ec7n \u00e1p l\u00e0 h\u00e0m, c\u00e1c d\u00f2ng \u0111i\u1ec7n l\u00e0 <\/span>bi\u1ebfn c\u00f3 d\u1ea1ng sau:<\/span><\/p>\n

\"\"C\u1eb7p ph\u01b0\u01a1ng tr\u00ecnh d\u1eabn n\u1ea1p c\u00f3 \u0111\u01b0\u1ee3c khi coi c\u00e1c d\u00f2ng \u0111i\u1ec7n l\u00e0 h\u00e0m c\u1ee7a c\u00e1c bi\u1ebfn \u0111i\u1ec7n \u00e1p:<\/span><\/p>\n

\"\"<\/span><\/p>\n

C\u1eb7p ph\u01b0\u01a1ng tr\u00ecnh h\u1ed7n h\u1ee3p:<\/span><\/p>\n

\"\"Trong \u0111\u00f3: rij ,gij ,hij\u00a0\u00a0t\u01b0\u01a1ng \u1ee9ng l\u00e0 c\u00e1c tham s\u1ed1 tr\u1edf kh\u00e1ng, d\u1eabn n\u1ea1p v\u00e0 h\u1ed7n h\u1ee3p c\u1ee7a tranzito.<\/span><\/p>\n

B\u1eb1ng c\u00e1ch l\u1ea5y vi ph\u00e2n to\u00e0n ph\u1ea7n c\u00e1c h\u1ec7 ph\u01b0\u01a1ng tr\u00ecnh tr\u00ean, ta s\u1ebd x\u00e1c \u0111\u1ecbnh \u0111\u01b0\u1ee3c c\u00e1c\u00a0tham s\u1ed1 vi ph\u00e2n t\u01b0\u01a1ng \u1ee9ng c\u1ee7a tranzito. V\u00ed d\u1ee5:<\/span><\/p>\n

\"\"* S\u01a1 \u0111\u1ed3 t\u01b0\u01a1ng \u0111\u01b0\u01a1ng c\u1ee7a tranzito: C\u00f3 2 lo\u1ea1i c\u01a1 b\u1ea3n l\u00e0 s\u01a1 \u0111\u1ed3 t\u01b0\u01a1ng \u0111\u01b0\u01a1ng t\u1ef1 nhi\u00ean v\u00e0 s\u01a1 \u0111\u1ed3 t\u01b0\u01a1ng \u0111\u01b0\u01a1ng thay th\u1ebf.<\/span><\/p>\n