Differential Amplifier

[Ungen]

I have big problems understanding this problem. It's an earlier exams assignment.
I think my biggest problem is that I don't understand how the configuration on Q2 works. Looks for that the Q2 base get 0 volt..
Think a better translation on the last question might be " current source ".

Thanks in advance for any tips or solution.
Regards
Anders

 

[LvW]

I think, you have no other chance than to assume for both transistors a biasing DC voltage between base and emitter of Vbe=(0.65...0.7) volts. The exact voltage is not known and is not too important because of of the negative feedback effect of Re. Starting with such an assumption it shouldn`t be a problem fpr you to calculate the quiescent DC current through the transistors (can be assumed to be equal).

 

[Kabelsalat]

For the question D (the printed part not translated) it says that the 8.2kΩ resistor is switced by a current source.

btw. It's a bad practice not to labeling all components, as the resistors (that is to blame the assignment paper).

 

[Ungen]

Thanks