I have some confusion regarding the real SC-CMFB circuit. When i use ideal CMFB everything seems good. But when I use SC-CMFB then I look at PSS and PAC analysis to find the gain and phase margin, they do not come good. Now after PSS/PAC analysis, I can not see DC operating point ( in fact one can see the DC operating points but they are not correct). Now how to know what to change to get the desired gain and phase margin. Also do you know how to check the stability of the CMFB loop?