Share
Explore BrainMass

AC/DC BJT transisitor Circuit Analysis

For the circuit in the image, Beta=120, VCC=5V, Va=100V, and Rb=25kohms. Determine Vbb and RC such that Rpi=5.4kOhms and the Q-point is in the center of the load line.

I have a formula for Rpi=(Vt*Beta)/Icq. From this I found Icq=1.25x10^-4 Amps.

However, is this a correct way to determine Icq? The question said to determine the values such that the Q-point is in the center of the load line. How do I draw the graph to find out the center value if I don't know Vce?

KVL around to ce loop relates RC and VCE: Rc=(5v-Vce)/(1.25x10^-4) if I can use the Icq from earlier.

Diagram is attached.

Please help. What am I missing? Thank you.

Attachments

Solution Preview

Hi,
The way you got Icq is fine. But the value looks too small. Please check the unit just in case.
The ...

Solution Summary

The solution provides aid and guidance to the problem concerning AC/DC BJT tansistor circuit analysis.

$2.19