# Simple BJT Question, Obtaining Ie

Discussion in 'Homework Help' started by jegues, Apr 20, 2011.

1. ### jegues Thread Starter Well-Known Member

Sep 13, 2010
735
45
Hello everyone.

Can someone please explain to me how he obtains the value of Ie here? I'm just not seeing it.

What is the effect of the capacitors in terms of our analysis? I'm sure there's an obvious conclusion to be made because there capicatance is infinite.

Thanks again!

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2. ### Jony130 AAC Fanatic!

Feb 17, 2009
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1,284
I also not seeing it.
For me Ie = 0.33mA

PS. And this amplifier we refers as Common base amplifier

3. ### Jony130 AAC Fanatic!

Feb 17, 2009
4,581
1,284
In this case capacitor act like a short-circuit for AC signal

4. ### jegues Thread Starter Well-Known Member

Sep 13, 2010
735
45
How do you know that Ie = 0.33mA?

Doesn't some of the current from the current source branch out to the resistances as well?

5. ### Jony130 AAC Fanatic!

Feb 17, 2009
4,581
1,284
Do you mean RB = 100K resistor??
And you also have to remember that in BJT
Ie = Ib + Ic