Re: [IBIS-Users] C_Comp measurement using HSPICE AC analysis

From: Andrew Ingraham <a.ingraham_at_.....>
Date: Thu Mar 03 2005 - 06:47:59 PST
> ...  The I/O is tristated, and then AC analysis is used to
> get the ZIN with that gives you "j x omega x Cin" with Cin = C_comp.

This would work if the die has no package.  If there is any C_pin, you'd
need to subtract that from the measurement and leave the remainder to
C_comp.  And depending on frequency, the effect of L_pin may alter how
C_comp becomes part of the total Cin.

As a first try, it would probably be better to construct a passive SPICE
circuit consisting of package parasitics and C_comp, and figure out how much
C_comp is needed to get the Cin that you had extracted.

Regards,
Andy


|------------------------------------------------------------------
|For help or to subscribe/unsubscribe, email majordomo@eda.org
|with just the appropriate command message(s) in the body:
|
|  help
|  subscribe   ibis       <optional e-mail address, if different>
|  subscribe   ibis-users <optional e-mail address, if different>
|  unsubscribe ibis       <optional e-mail address, if different>
|  unsubscribe ibis-users <optional e-mail address, if different>
|
|or email a written request to ibis-request@eda.org.
|
|IBIS reflector archives exist under:
|
|  http://www.eda.org/pub/ibis/email_archive/  Recent
|  http://www.eda.org/pub/ibis/users_archive/  Recent
|  http://www.eda.org/pub/ibis/email/          E-mail since 1993
Received on Thu Mar 3 07:02:44 2005

This archive was generated by hypermail 2.1.8 : Thu Mar 03 2005 - 07:03:27 PST