# CE/CB BJT Amplifier(s) + Load Lines!

This diagram from a lab assignment is not making sense to me...any help would be greatly appreciated.

I don't understand what $$\I_{C_\max}\cdot R_e\$$ is and why it appears on this diagram. Even if it should be on the diagram, why is it only $$\R_e \$$ and not $$\R_{DC}\$$? Shouldn't $$\V_{CE_\min}\$$ be from $$\0\mathrm{V}\$$ to $$\\sim0.3\mathrm{V}\$$?

When calculating $$\R_e\$$ and $$\R_c\$$, this equation is used I've tried leaving the term I don't understand out (probably a bad idea lol), which causes either $$\R_c\$$ or $$\R_e\$$ to be negative and I have tried calling it $$\I_{C_\max}\cdot R_{DC}\$$, which results in two negative resistances...

Side question: For a Common base amplifier, would $$\R_{AC}\$$ include $$\R_s\$$ (the signal resistance)? Thus should be $$\R_C\parallel R_L + R_e\parallel R_s\$$?

Thanks a ton!

• Look here electronics.stackexchange.com/questions/301617/… and notice how the voltage across RE resistor change with an input signal. – G36 Mar 9 at 6:11
• You are thinking of Vce(sat ) instead of Vce(min for linear operation. THis depends on harmonic distortion spec or variation of sine asymmetry which can easily be 10% when Vce< 1V and at high current <2V . I would choose a number in that preferred linear range depending on Ic/Ic max – Sunnyskyguy EE75 Mar 9 at 9:02