- #1
likephysics
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Homework Statement
a)Find R1
b)Find the change in IC if Re varies by 5%.
Given:
Ic = 0.25mA
β=100
(see attached ckt)
Homework Equations
The Attempt at a Solution
Ic=0.25mA, Ib=0.0025mA
Vbe = 0.6956V
Ie=Ic+Ib = 0.2525mA
Re = 200*0.2525 = 50.5mV
Found R1 by applying KCL at base.
(Vcc-Vbe-Vre)/R1 = (Vbe+Vre)/10k + Ib
R1=22.75K
For part b) Re be +5% = 210 ohms
Vre = 210*Ie= 53mV
Is this even correct, I took the old Ie. What next?
I can't use any equations having Vbe or Ib since they change with increase in Vre.