Discussion in 'Homework Help' started by chaosweapon, May 3, 2009.

1. ### chaosweapon Thread Starter Member

Nov 14, 2008
15
0
Is the AC Load Line of the Common Collector calculated in the same way as that of the Common Emitter?

ie are the following equations applicable to CCs:
ic(sat) = IC + VCE/(RE//RL)
vce(cutoff) = VCE + IC(RE//RL)

If not, what are the correct equations?

And what about a swamped Common Emitter?

2. ### PRS Well-Known Member

Aug 24, 2008
989
35
Your questions confuse me. Here's a CC amp with its load line. Hope it helps!

File size:
33.1 KB
Views:
44
3. ### chaosweapon Thread Starter Member

Nov 14, 2008
15
0
Thanks. That means that those equations are also valid for CCs.

Edit: You posted the DC Load Line. How would the AC load line be for that circuit?

Last edited: May 3, 2009
4. ### chaosweapon Thread Starter Member

Nov 14, 2008
15
0
Could it be possible that the Common Collector does not have a load line?

5. ### PRS Well-Known Member

Aug 24, 2008
989
35
You brought up a good point. I've never worried about loadlines with CCs. I suppose the AC and DC loadlines are the same because there is no gain. The signal merely rides on top of the DC voltage Ve. On the load diagram you can envision a sine wave riding to the left and right of the Ve point. Note that if Ve is right in the middle then clipping only occurs when the signal crosses either Vcc or ground.