Designer’s Guide Community :: Forum

Welcome, Guest. Please Login or Register. Please follow the Forum guidelines.

Aug 17^th, 2024, 2:20pm

	HomeHelpSearchLoginRegisterPM to admin

The Designer's Guide Community Forum › Design › Analog Design › folded cascode...

‹ Previous topic | Next topic ›

Pages: 1

Send Topic

Print

folded cascode... (Read 4185 times)

somisetty Community Member Offline Posts: 64	folded cascode... Jun 24^th, 2009, 11:51pm hi all, can u tell me why the name folded cascode? why miller compensation not required in folded cascode OTA? Thanks
Back to top	IP Logged

raja.cedt Senior Fellow Offline Posts: 1516 Germany	Re: folded cascode... Reply #1 - Jun 25^th, 2009, 1:14am hi, because it is single stage..so how you use miller compensation...generally in two stage miller compensation is required but the same two stage gain you will get in single stage if you use folded. Thanks, Rajasekhar.
Back to top	IP Logged

nobody Community Member Offline Posts: 75	Re: folded cascode... Reply #2 - Jun 25^th, 2009, 2:32am The input pair is folded so that the input range is improved. Sometimes, the miller effect will have effects on PM.
Back to top	IP Logged

raja.cedt Senior Fellow Offline Posts: 1516 Germany	Re: folded cascode... Reply #3 - Jun 25^th, 2009, 5:40am you mean miller effect at the input tx gate..any how your drain is low impedance because of cascoding..no problem Thanks, rajasekhar.
Back to top	IP Logged

nobody Community Member Offline Posts: 75	Re: folded cascode... Reply #4 - Jun 25^th, 2009, 7:42pm Basically, you assume the impedance frequency is 1/gm, which is right @ high frequency and the gain is gm,inp/gm,cascoded. However, the impedance is not low @ low frequency and you can try to derive the gain @ low frequency and see what you have.
Back to top	IP Logged

raja.cedt Senior Fellow Offline Posts: 1516 Germany	Re: folded cascode... Reply #5 - Jun 25^th, 2009, 9:30pm yaa..its correct now you catch the correct point..pole at the input device is non dominant ..so it will be come into action at high frequency..so whats the problem.. Thanks, Rajasekhar.
Back to top	IP Logged

nobody Community Member Offline Posts: 75	Re: folded cascode... Reply #6 - Jun 25^th, 2009, 11:46pm It is my fault saying about the miller effect on PM. The miller effect will show up in SC ckt and has the influence on the loop gain. Sorry about that. The non-dominant pole is basically determined by PMOS or NMOS input pair.
Back to top	IP Logged

Pages: 1

Send Topic

Print

‹ Previous topic | Next topic ›

The Designer's Guide Community Forum » Powered by YaBB 2.2.2!
YaBB © 2000-2008. All Rights Reserved.