Jul 26, 2005 #1 A arpit_655 Newbie level 5 Joined Jul 26, 2005 Messages 9 Helped 0 Reputation 0 Reaction score 0 Trophy points 1,281 Activity points 1,355 Hi all, i`ve designed a gain boosted folded cascode fully diff op-amp with 100db gain & 700MHz UGB. i tried with putting differential-to-single-ended stage but it was causing the op-amp to be highly Unstable... could someone tell me how to configure a fully differential op-amp as voltage follower (unity gain feedback). Waiting for a quick reply.. Regards.
Hi all, i`ve designed a gain boosted folded cascode fully diff op-amp with 100db gain & 700MHz UGB. i tried with putting differential-to-single-ended stage but it was causing the op-amp to be highly Unstable... could someone tell me how to configure a fully differential op-amp as voltage follower (unity gain feedback). Waiting for a quick reply.. Regards.
Jul 27, 2005 #2 E eda4you Full Member level 5 Joined Sep 17, 2002 Messages 256 Helped 24 Reputation 48 Reaction score 11 Trophy points 1,298 Activity points 2,325 Make simulation and make a bode plot. (Look also for a rebound of the phase). You should have at least 60° phase margin.
Make simulation and make a bode plot. (Look also for a rebound of the phase). You should have at least 60° phase margin.
Jul 27, 2005 #3 A arpit_655 Newbie level 5 Joined Jul 26, 2005 Messages 9 Helped 0 Reputation 0 Reaction score 0 Trophy points 1,281 Activity points 1,355 i have 70 deg of phase margin while taking differential output.... but when i put next stage to get single ended output then phase reached -220 deg making the op-amp highly unstable.... is it possible to use a fully differential op-amp as a buffer in chage scaling D/A converter... plz suggest a way...
i have 70 deg of phase margin while taking differential output.... but when i put next stage to get single ended output then phase reached -220 deg making the op-amp highly unstable.... is it possible to use a fully differential op-amp as a buffer in chage scaling D/A converter... plz suggest a way...
Jul 28, 2005 #4 B Btrend Advanced Member level 1 Joined Dec 26, 2003 Messages 422 Helped 71 Reputation 142 Reaction score 14 Trophy points 1,298 Activity points 3,984 arpit_655 said: i have 70 deg of phase margin while taking differential output.... but when i put next stage to get single ended output then phase reached -220 deg making the op-amp highly unstable.... is it possible to use a fully differential op-amp as a buffer in chage scaling D/A converter... plz suggest a way... Click to expand... do u include ur next stage as load while in runing AC simulation of ur differential amp ?
arpit_655 said: i have 70 deg of phase margin while taking differential output.... but when i put next stage to get single ended output then phase reached -220 deg making the op-amp highly unstable.... is it possible to use a fully differential op-amp as a buffer in chage scaling D/A converter... plz suggest a way... Click to expand... do u include ur next stage as load while in runing AC simulation of ur differential amp ?
Jul 29, 2005 #5 A arpit_655 Newbie level 5 Joined Jul 26, 2005 Messages 9 Helped 0 Reputation 0 Reaction score 0 Trophy points 1,281 Activity points 1,355 next stage is a differential amplifier with active current mirror...