ho28.l25_ota3

ho28.l25_ota3 - OTA Feedback Circuits Feedback Circuits...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
1 OTA Feedback Circuits (Part III) R. Dutton, B. Murmann Stanford University R. Dutton, B. Murmann 1 EE114 (HO #28) Poor Man’s OTA Circuit With Cascodes R. Dutton, B. Murmann 2 Objective: increase low frequency loop gain Æ precision EE114 (HO #28)
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 AC Equivalent Model ( ) () r int v on on m on on m on on r int v op op mp op op mp op op a r r g r r ' g r R a r r g r r g r R 2 2 2 1 1 + = + = Cascodes help increase low x s f f C C C C + + = β ( ) op on r int v op on o r r a R R R 2 = o m R G T β = 0 R. Dutton, B. Murmann 3 frequency loop gain roughly by the intrinsic device gain – ~100 in the EE114 technology EE114 (HO #28) Impact of C gdn •Z c ~ 1/g m ’ if R op >> r on – But this is not the case here Using the result from lecture 10 DC near 1 1 1 R Z r sC R ' g Z op on Ltot op m c + R. Dutton, B. Murmann 4 EE114 (HO #28) s frequencie high at 1 near ' g Z r r ' g m c op on m c [] c on m gdn gs x Z r G ) s ( K ; C ) s ( K C C 2 1 2 + =
Background image of page 2
3 K versus Frequency 10 0 10 1 |K(f)| ( ) op on m r r G 2 8 0 . ' g g m m R. Dutton, B. Murmann 5 10 0 10 2 10 4 10 6 10 8 10 10 f [Hz] EE114 (HO #28) on Ltot r C π 2 1 Resulting Model High frequencies
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/09/2009 for the course EE 114 at Stanford.

Page1 / 9

ho28.l25_ota3 - OTA Feedback Circuits Feedback Circuits...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online