ce amplifier singlestage
NiCeMaN said:
yes voltage gain =Vo/Vin = -Rc/Re
If capacitor not present it will be Rc/(Re+RE)
Am i rite?
What is Re ???
OK, independent on this question and because - up to now - nobody gave you an answer, here are some background information to you:
1.) The formula Rc/(Re+RE) is a rather good approximation (without capacitor acroos RE) if Re=1/gm with gm=transconductance of the BJT. And in most cases you can neglect 1/gm<<RE.
2.) However, if there is a load, you have to replace RC by RC||Rload
3.) But for your values of course: Vo/Vin=gain<1.
4.) Thus, you have to reduce RE considerably.
5.) As a consequence, you have to recalculate R1 and R2
6.) Recommendation for
one possible set of values (out of 1000 alternatives):
6.1) Choose Rc=5 k and Ic=1mA >>>Rc||Rload=3.33 k
6.2) Take RE= 500 ohms (approximately)
6.3) This leads to a gain of app. 6.6 (16 dB)
6.4) Calculate R2=(0.6+Ic*RE)/Iq with Iq=9*IB=9*Ic/B
with B=current gain of BJT
6.5) Calculate R1=(12-(0.6+Ic*RE))/(10*IB)
Addendum at 17:30 I have corrected an error i line 2 (RE replaced by RC)