{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Chapter 4 BJT3

# Chapter 4 BJT3 - Chapter 4 Bipolar Junction Transistor(BJ T...

This preview shows pages 1–8. Sign up to view the full content.

SJTU J. Chen 1 3/2/12 Chapter 4 Bipolar Junction Transistor (BJ T)

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

View Full Document
3/2/12 2 J.P. Chen The analysis process (1) Determine the dc operating point of the BJT, in partic ular I c (2) Calculate the values of the small-signal model param eters: (3) Give the AC circuit: eliminate the dc source by replac ing each dc voltage source with a short circuit and e ach dc current source with an open circuit (4) Replace the BJT with one of its small-signal equivale nt circuit models (5) Analyze the resulting circuit to determine the require d quantities, e.g. voltage gain, input resistance and o utput resistance m E T e m T C m g I V r g r V I g 1 , , 2245 = = = β π
3/2/12 3 J. P C h e n Ø Expression for the output resistance. Ø Output resistance represents the Early Effect(or base width modulation) Augmenting the Hybrid- Model ' 1 . C A const v CE C o I V v i r BE = = - =

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

View Full Document
3/2/12 4 J. P C h e n Models derived from npn type transistor apply eq ually well to pnp transistor with no changes of pol arities. Because the small signal can not change t he bias conditions, small signal models are indep endent of polarities. No matter what the configuration is, model is uniq ue. Which one to be selected is only determined b y the simplest analysis. Models for pnp Type
3/2/12 5 J.P. Chen Summary of model parameters (1) Model parameters in terms of DC bias currents: (2) Model parameters in terms of g m : (3) Model parameters in terms of re: (4) Relationships between αandβ : = = = C T B T T C m I V I V r V I g β π C A o C T E T e I V r I V I V r = = = α m m e g r g r β α π = = , ( 29 e m e e m r r g r r r g 1 1 , 1 , = + + = = π π β α α β β β α α α β - = + + = - = 1 1 1 , 1 , 1

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

View Full Document
3/2/12 6 J. P C h e n Homework 4.36; 4.54; 4.57
3/2/12 7 J. P C h e n Part 1. Physical Operation and Current-Volt age Characteristics.

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

View Full Document
This is the end of the preview. Sign up to access the rest of the document.
• Fall '10
• ChengJianping
• Bipolar junction transistor, voltage gain, small signal, discrete circuit bias, classical discrete circuit

{[ snackBarMessage ]}

### Page1 / 31

Chapter 4 BJT3 - Chapter 4 Bipolar Junction Transistor(BJ T...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online