tompham
Full Member level 2
Hi all
I have problem design 2 stage fully diff opamp with sc cmfb. I am using 0.18um from tsmc process. When I run w/o sc cmfb the gain about 65db, phase margin 64 degree and GBW~540Mhz. If sc cmfb is connected the gain a little bit reduce to ~60db but outputs from negative and positive have diff result for GBW and phase margin and GBW reduce a lot 376Mhz compare to 540Mhz. I knew the sc cmfb make this happen but I have no idea how to fix this. I have no spectreRF tool to design and run sc simulation. I need help from anyone. Thanks a lot
BTW: anyone know any free tool to run sc beside spectreRF from cadence please show me website to download it.
I have problem design 2 stage fully diff opamp with sc cmfb. I am using 0.18um from tsmc process. When I run w/o sc cmfb the gain about 65db, phase margin 64 degree and GBW~540Mhz. If sc cmfb is connected the gain a little bit reduce to ~60db but outputs from negative and positive have diff result for GBW and phase margin and GBW reduce a lot 376Mhz compare to 540Mhz. I knew the sc cmfb make this happen but I have no idea how to fix this. I have no spectreRF tool to design and run sc simulation. I need help from anyone. Thanks a lot
BTW: anyone know any free tool to run sc beside spectreRF from cadence please show me website to download it.