EE 330 Lect 27 Fall 2011

EE 330 Lect 27 Fall 2011 - EE 330 Lecture 27 Small-signal...

Info iconThis preview shows pages 1–9. Sign up to view the full content.

View Full Document Right Arrow Icon
EE 330 Lecture 27 Small-signal model of BJT Small-Signal Model Extension Applications of the Small-signal Model
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
      3 2 1 3 3 3 2 1 2 2 3 2 1 1 1 V , ,V V f I V , V f I V , V f I 4-terminal small-signal network summary I 1 I 2 I 3 V 1 V 2 V 3 4-Terminal Device 3 23 2 22 1 21 2 v y y y v v i 3 33 2 32 1 31 3 v y y y v v i 3 13 2 12 1 11 1 v y y y v v i y 11 y 12 V 2 V 1 i 1 y 13 V 3 y 22 y 21 V 1 V 2 i 2 y 23 V 3 y 33 y 31 V 1 V 3 i 3 y 32 V 2   Q V V j 3 2 1 i ij V V , V f y Small signal model: Review from Last Lecture
Background image of page 2
3-terminal small-signal network summary Small signal model: y 11 y 22 y 12 V 2 y 21 V 1 V 1 V 2 i 1 i 2   Q V V j 2 1 i ij V ,V V f y I 1 I 2 V 1 V 2 3-Terminal Device 2 22 1 21 2 V V i y y 2 12 1 11 1 V V i y y     2 1 2 2 2 1 1 1 V f I V f I Review from Last Lecture
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Small-Signal Model       1 1 1 2 3 2 2 1 2 3 3 3 1 2 3 ,, g g g i V V V i V V V i V V V I 1 I 2 I 3 V 1 V 2 V 3 4-Terminal Device 3 23 2 22 1 21 2 V y y y V V i 3 33 2 32 1 31 3 V y y y V V i 3 13 2 12 1 11 1 V y y y V V i   Q V V j 3 2 1 i ij V V , ,V V f y 2 Consider 2-terminal network Review from Last Lecture
Background image of page 4
Small Signal Model of MOSFET DQ I O g   OX GSQ T W μC V V L m g  g O g m V GS V GS G D S Alternate equivalent expressions for g m :       1 22 DQ OX GSQ T DSQ OX GSQ T WW I= μC V V V μC V V 2L 2L   OX GSQ T W μC V V L m g OX DQ W 2μC I L m g  2 DQ m GSQ T I g VV Review from Last Lecture
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Small signal analysis example Consider again: R M 1 V IN V OUT For λ=0, g O = λI DQ = 0 1 OUT m V IN O Vg A V g R   g O g m V GS V GS V IN V OUT R   DQ v SS T 2I R A VV Same expression as derived before More accurate gain can be obtained if λ effects are included and does not significantly increase complexity of small signal analysis Review from Last Lecture
Background image of page 6
Small Signal Model of BJT 3-terminal device V CE I C Forward Active Cutoff Saturation Usually operated in Forward Active Region when small-signal model is needed 1 BE t V V CE C S E AF V I J A e V     t BE V V E S B e β A J I Forward Active Model: Q C 21 BE VV I y V m g 
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Small Signal Model of BJT Q B 11 BE VV I y V g    2 2 1 2 I f V,V   Q i 1 2 ij j y V   1 1 1 2 I Small-signal model: Q B 12 CE I y V Q C 22 CE I y V O g t BE V V E S B e β A J I 1 BE t V V CE C S E AF V I J A e V 
Background image of page 8
Image of page 9
This is the end of the preview. Sign up to access the rest of the document.

This document was uploaded on 01/31/2012.

Page1 / 33

EE 330 Lect 27 Fall 2011 - EE 330 Lecture 27 Small-signal...

This preview shows document pages 1 - 9. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online