ee484
Full Member level 3
Hi, all.
Suddenly, I am wondering how I got bode plots of common source amplifiers.
As you know, without dominant pole consideration, the gain of the common source amp is -GmRout. There IS a negative sign!!!
Since bode plots show both magnitude and phase reponse, the magnitude only indicates the absolute value of the amplitude (of course, in the bode plot, in dB) - So, there is no sign information!
Now, we typically starts with 0 degree until we hit the 1/10 of the (dominant) pole frequency. However, ISN'T -180 (or 180) corresponding to a negative sign?? With 0 degree phase shift, at DC, the voltage gain should be GmRout!!
I know I am wrong here..., but I am blind for it..Please let me open my eyes to see the truth^^
Please let me know....
Thanks,
Suddenly, I am wondering how I got bode plots of common source amplifiers.
As you know, without dominant pole consideration, the gain of the common source amp is -GmRout. There IS a negative sign!!!
Since bode plots show both magnitude and phase reponse, the magnitude only indicates the absolute value of the amplitude (of course, in the bode plot, in dB) - So, there is no sign information!
Now, we typically starts with 0 degree until we hit the 1/10 of the (dominant) pole frequency. However, ISN'T -180 (or 180) corresponding to a negative sign?? With 0 degree phase shift, at DC, the voltage gain should be GmRout!!
I know I am wrong here..., but I am blind for it..Please let me open my eyes to see the truth^^
Please let me know....
Thanks,