xinzhao
Newbie level 1
Hi guys,
I've a question for calculating the transfer function of a 3 stage NMC op amp (see figure).
I assume each stage output resistance is infinite. My calculation is based on the output current of each gm stage. Three gm stages give me three equations. For example, first equation in the figure is gm1 output current equals the current flowing through C1. The Vout/Vin result shows correct pole locations, but only one zero. The NMC transfer function should have two zeros but I can not get the second one from my calculation. Anyone have any idea about what I'm missing? Thanks.
I've a question for calculating the transfer function of a 3 stage NMC op amp (see figure).
I assume each stage output resistance is infinite. My calculation is based on the output current of each gm stage. Three gm stages give me three equations. For example, first equation in the figure is gm1 output current equals the current flowing through C1. The Vout/Vin result shows correct pole locations, but only one zero. The NMC transfer function should have two zeros but I can not get the second one from my calculation. Anyone have any idea about what I'm missing? Thanks.