Hi
I am trying to solve this small signal problem
Assume
VC = VCC / 2
β= 80
and VT = 26 mV
Find the small-signal voltage gain Av = Vo / VS
I am not sure how to find the voltage Vb,Vs and draw the small signal model
For the DC part
Vcc=Ic*Rc+VC+IERE
8=β*Ib*2.5k+4+(1+β)*Ib*600
Ib=0.01609mA
For the AC part
Rπ=VT/ib
=1540ohm
I am not sure how to find the voltage Vb,Vs
Vo=-βib*Rc
Vb=ib*Rπ + ib*(1+β)*Re
Vb=Vs ?
Av=Vo/Vs
Av=Vo/Vb*Vb/Vs
Av=[-βib*Rc]/[ib*Rπ+(1+β)*ib*Re]*1
Av=-4
I am trying to solve this small signal problem
Assume
VC = VCC / 2
β= 80
and VT = 26 mV
Find the small-signal voltage gain Av = Vo / VS
I am not sure how to find the voltage Vb,Vs and draw the small signal model
For the DC part
Vcc=Ic*Rc+VC+IERE
8=β*Ib*2.5k+4+(1+β)*Ib*600
Ib=0.01609mA
For the AC part
Rπ=VT/ib
=1540ohm
I am not sure how to find the voltage Vb,Vs
Vo=-βib*Rc
Vb=ib*Rπ + ib*(1+β)*Re
Vb=Vs ?
Av=Vo/Vs
Av=Vo/Vb*Vb/Vs
Av=[-βib*Rc]/[ib*Rπ+(1+β)*ib*Re]*1
Av=-4
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