# 4310 week11 cb cc amp config

Post on 18-Nov-2015

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• 18

CB Amplifier

Ai=

• 0.5mA

1K100K

50

50

+

?

?

.

250.5

5050 50 .

19.8 0.5 .

1 100 150 .

||

• 20

CC Amplifier

• +9V +9V

100K

10K

1K 1K

20?

?

???

9 0.7

1 1001.

1 1.44 .

1.44 0.7 .

100 ||{ 1 1 ||1 ,.

.

ACDC

.100

10 100 1 1 1

100 10 1 17.4 1 1||

|| ||

.

KVL

• 25

Table 5.6

CE CE+RE

CB CC

• 26

Transistor as a switch: Cut-off and Saturation

If vI < 0.5 V EBJ is offand CBJ is off

Thus the transistor is in cut-off mode

iB = 0 , iC = 0 , iE = 0

In Active mode VBE 0.7 V vI > VBE

iB = (vI VBE)/RB =(vI 0.7)/RB , iC= iB

To verify that the transistor is in active mode:

vC = VCC iC RC if vCB>0 active

• 27

When VC = VB Edge of Saturation

IC=(VCC-VB)/RC=(VCC-0.7)/RC= IB

VI = RBIB + VBE

• 28

If VCB0 Transistor enters Saturation 0.4V-0.6V

0.3V>VCE>0.1V

VCE=VBE+VCBVCEsat= 0.2V

In Deep Saturation

• 29

In Deep Saturation:

VCE = VCEsat = 0.2V

IC=ICsat=(VCC-VCEsat)/RC

ICsat= forced IB

The transistor in Deep Saturation is modeled as:

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