Question

A self bias circuit uses Si transistor, RC = 330 Ω, RE = 100 Ω and VCC = 12 V. Estimate the values of R1 and R2 required to provide a base current of 0.3 mA, so as to locate the operating point at ICQ = 18 mA and VCEQ = 4.25 V

Answer 1

I_C= I_E =I_cQ=18m A

Vc=4.25V

Vth- Rth*0.3*10^-3-0.7-100*18*10^-3=0

Vth- Rth*0.3*10^-3=2.5

Let Rth=100 ohm, R1-200ohm

R2=200ohm

Vth=2.53 volt