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There is a problem I have been dealing with for hours.

In my Electronic 1 lecture, small signal analysis was like this:

enter image description here

The small signal equivalent of this circuit in my lecture notes was this:

enter image description here

When they calculate the no load voltage gain Av they do not remove the Rc. To me, Rc is the load but they do not accept.

enter image description here

In this semester in Electronic 2 lecture, the topic is feedback of amplifier circuit and this time they accept Rc is load (effective load this time) and when they calculate the no load open-loop gain they remove the Rc.

Why? Which one is correct?

enter image description here

(I am sorry for my bad english)

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  • \$\begingroup\$ The 1st included the Rce leakage which tends to be high R, Early effect) using 1/hOE , the 2nd ignores it \$\endgroup\$
    – D.A.S.
    Commented Oct 14, 2020 at 17:14

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according to me Rc is load

Rc is not normally considered part of the load, but part of the amplifier circuit itself. The load is whatever is connected on the other side of the output coupling capacitor C2.

It's possible to design a common emitter amplifier where Rc is absent and the load provides the collector bias current, but that isn't what was done here.

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