The NPN bipolar transistor is used to operate in the middle

The NPN bipolar transistor is used to operate in the middle of active region. The transistor requires a collector current, I_c = 30 mA, when the output of the circuit, V_OUT, is at 5V. The transistor develops V_BE = 0.7 V in active region and maintains a current gain of 100, i.e. beta = I_C/I_B = 100. Use the ouput I-V curve below to compute R_B and R_C that satisfies the proper transistor operation.

Solution

when Q is Center of Active Region,

I_c=30mA

V_CE=5V

AT collector to emittor Loop

V_CC-I_CR_C-V_CE=0

R_C=V_CC-V_CE/I_C

R_C=10-5/30m

R_C=166.7ohm

I_B=30mA/100=0.3mA

Where in emitter to bases region

V_BB-I_BR_B-V_BE=0

(V_BB-V_BE)/I_B=R_B

R_B=(5-0.7)/0.3mA=14.3Kohm