Question

SIXTH ACTIVITY: Common Emitter Amplifier. Please do the computer simulations before or after the lab (it's recommended that you do them before) 1- Set up the following circuit. Part a) vdt) Use values of Vc, Ru and Rg that will assure that the transistor is in the active region. What's the value of VCE?

Answer 1

Given that: - A transistor bias circuit as shown below for this transistor to be in active mode of operation greaterthanorequalto 0.7 volts and greaterthanorequalto V_CE greaterthanorequalto 0.2 volt (if V_BE < 0.7 it will be in cut off) \r\n (If V_CE < 0.2 v it will beam saturation) choose large 'beta' and large value of R_B that I_B can be neglected choose _B = 10 times R_C consider V_SI = 0.7 volts as I_B times 0 Bropaciam R_B is zero } active mode of operation Hence V_CE = V_BE = 0.7 volts now choose V_CC such that I = V_CC - V_CE/R_C = V_CC - 0.7/R_C > 0 V_CC > 0.7 rightarrow choose V_CC = 5 volts so I tildeequal I_C = V_CC - V_CE/R_C = 5 - 0.7/12 > 0 choose any R_C i.e. R_C = 10 k ohm E_B = 10 times R_C = 100 k ohm