Talk About Network

Google


Register and Login
Nick
Password
Register create new account Sign up is FREE and you can post replies, new topics, bookmark posts and more!
Recover lost password


Electronic Equipment > Electronics Design > Capacitvely-loa...
Latest [ Topics | Posts ] Archive Post A New Topic Post a Reply
<< Topic < Post Post 1 of 24 Topic 32224 of 33980
Post > Topic >>

Capacitvely-loaded source follower

by "Andrew Holme" <ah@[EMAIL PROTECTED] > Jul 6, 2008 at 07:24 PM

I'm looking at problem 7, chapter 9 of T. Lee "The Design of CMOS 
Radio-frequency integrated circuits" regarding the input impedance of a 
capacitively-loaded source follower.  Cgd and rg are assumed zero.  DC 
biasing of the source is a constant-current sink so doesn't feature in the

AC analysis.  There is only Cgs and load capacitance CL.  It asks over
what 
range of load capacitance the real part of the input impedance is
negative? 
Is this a trick question?  I think it is for all CL:

Vg = Vgs + Vs

Vg =   Ig       (Ig + gm.Vgs)
     ------  +  -------------
     jw.Cgs         jw.CL


Vg =   Ig         1              Ig
     ------  +  ----- (Ig + gm.------)
     jw.Cgs     jw.CL          jw.Cgs


Vg   jw.CL + jw.Cgs + gm
-- = -------------------
Ig      jw.CL . jw.Cgs


Vg   -gm - jw(Cgs+CL)
-- = ----------------
Ig    w^2 . Cgs . CL


View in a fixed pitch font.
 




 24 Posts in Topic:
Capacitvely-loaded source follower
"Andrew Holme"   2008-07-06 19:24:56 
Re: Capacitvely-loaded source follower
Jim Thompson <To-Email  2008-07-06 11:48:27 
Re: Capacitvely-loaded source follower
"Andrew Holme"   2008-07-06 20:06:10 
Re: Capacitvely-loaded source follower
"Michael A. Terrell&  2008-07-06 20:16:40 
Re: Capacitvely-loaded source follower
Jim Thompson <To-Email  2008-07-06 17:38:12 
Re: Capacitvely-loaded source follower
krw <krw@[EMAIL PROTEC  2008-07-07 19:03:50 
Re: Capacitvely-loaded source follower
"Michael A. Terrell&  2008-07-07 19:09:56 
Re: Capacitvely-loaded source follower
Jim Thompson <To-Email  2008-07-07 16:20:03 
Re: Capacitvely-loaded source follower
"Michael A. Terrell&  2008-07-07 19:52:45 
Re: Capacitvely-loaded source follower
Wimpie <wimabctel@[EMA  2008-07-06 13:49:47 
Re: Capacitvely-loaded source follower
"Andrew Holme"   2008-07-06 22:48:10 
Re: Capacitvely-loaded source follower
Jim Thompson <To-Email  2008-07-06 13:48:09 
Re: Capacitvely-loaded source follower
"Andrew Holme"   2008-07-06 22:36:02 
Re: Capacitvely-loaded source follower
Jim Thompson <To-Email  2008-07-06 14:49:30 
Re: Capacitvely-loaded source follower
"J.A. Legris" &  2008-07-07 04:48:00 
Re: Capacitvely-loaded source follower
Jim Thompson <To-Email  2008-07-07 07:30:22 
Re: Capacitvely-loaded source follower
"Tim Williams"   2008-07-07 11:43:41 
Re: Capacitvely-loaded source follower
Jim Thompson <To-Email  2008-07-07 09:50:31 
Re: Capacitvely-loaded source follower
"Michael A. Terrell&  2008-07-07 12:45:16 
Re: Capacitvely-loaded source follower
Paul Hovnanian <paulh@  2008-07-07 12:14:40 
Re: Capacitvely-loaded source follower
Jim Thompson <To-Email  2008-07-07 13:56:53 
Re: Capacitvely-loaded source follower
"Michael A. Terrell&  2008-07-07 18:10:47 
Re: Capacitvely-loaded source follower
Frank Miles <fpm@[EMAI  2008-07-07 10:07:41 
Re: Capacitvely-loaded source follower
"Andrew Holme"   2008-07-07 19:33:44 

Post A Reply:
  Go here to Signup

AddThis Feed Button


About - Advertising - Contact - Frequently Asked Questions - Privacy Policy - Terms of Use - Signup

Contact
tan12V112 Sat Nov 22 11:37:01 CST 2008.