I'm trying to simulate a common-emitter amplifier with a BJT and check that the results match with the equations I have.
The circuit I have is basically this:
This is the simulation: https://easyeda.com/editor#mode=sim,id=e10ea3e41e3d46f0b3a0bdef250a14ac. (you can simulate it by pressing F8)
I input 1.2 V
and I'm expecting an output of 6.33 V
, but I'm getting 0.1 mV
approx. according to the simulator. I suspect that I have misinterpreted the BJT datasheet, let me explain:
The BJT that is supposed to be used by the simulator is 2N2222
whose datasheet is here: https://datasheet.lcsc.com/szlcsc/1809200018_ST-Semtech-2N2222A_C118536.pdf
According to the above, the expected DC gain (beta) for this BJT is 75 when iC
is 10 mA
. So I have found an RI
that causes iC
to be 11 mA
just in case:
iC = 11 mA
Vi = 1.2 V
iC = beta * (Vi - 0.6) / RI
which gives me RI = 4k ohms
approx.
I calculate the expected output voltage with the following formula:
vOUT = Vd - ( ((vIN - 0.6) / RIN) * beta * RL )
Given that RI = 4k ohms
, Vd = 10 V
, vIN = 1.2 V
beta = 75
, and choosing an RL = 500 ohms
, the above equation gives 6.3325 V
.
However, as explained, the simulator gives me 0.1 mV
approx. What am I doing wrong?
PD.: you can check my formulas here