Post by gaom9 on Apr 24th, 2008, 6:41am
Hi,
I have some questions about the parameters of the apmlifier design.
I want to know what is the feedback factor F and it is defined as F=Cf/(Cs+Ci+Cf) in common source with Cf feedback factor, but this factor will be use in the diff pair amp design which do not have Cf capacitor. What does this factor do, please?
And about the noise factor, does it make the noise the campare to the noise from input pair, so the noise can be describe to the input pair only? And also the noise will be described to Cleff, what is Cleff?
About the Cleff. The Cleff is calculate from the DR, noise factor, and feedback factor F. It is to say increase the Cleff in order to make the DR meet the requirement. Is this Cleff the minimal capacitor Load of the amp the ensure the DR of it?
But if the Cleff is the minimal load capacitor, when we use this design in a circuit, the load capacitor will not be as large as Cleff(it is about 5pF), so the DR will decrease, do we need to ensure value of the Cleff?
About the ε of it, it is the error. But how to define it, please?
I am sorry to ask so many questions here.
But these parameters were not mention in Razavi and Allen's book.
Is there any book or paper about these parameters, please?
Thank you.
Best regards!
