I am currently designing a cascode amplifier that is suppose to have a gain of 97.8 and the corner frequency less than 200Hz using only BJT transistors, or more specifically, 2N3904. Ic current is to be 1ma and power supply is to be 15V-gnd. Out put is suppose to be 2V peak to peak with no distortion.
After a whole bunch of calculations, I was able to determine the proper values for all parts, as listed in one of the files named cascode amp design calculations.
Now you may ask: it looks fine, so what's the problem? Take a look at the scale of my simulation generated from PSpice. How on earth did I get 100V when none of my sources is more than 15V?
The simulation is suppose to show me the input curve and the output curve, allowing me to calculate the gain. But that is a bit difficult right now.
If anyone has any ideas, please let me know.
The design calculations are included for your convinence, just incase I made a mistake and I missed it. I have also included the simulation profile as well.
I used OrCAD Capture CIS 15.7, and PSpice to simulate this circuit.
Thanks very much,
Davy
After a whole bunch of calculations, I was able to determine the proper values for all parts, as listed in one of the files named cascode amp design calculations.
Now you may ask: it looks fine, so what's the problem? Take a look at the scale of my simulation generated from PSpice. How on earth did I get 100V when none of my sources is more than 15V?
The simulation is suppose to show me the input curve and the output curve, allowing me to calculate the gain. But that is a bit difficult right now.
If anyone has any ideas, please let me know.
The design calculations are included for your convinence, just incase I made a mistake and I missed it. I have also included the simulation profile as well.
I used OrCAD Capture CIS 15.7, and PSpice to simulate this circuit.
Thanks very much,
Davy
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