Subject: RE: [IBIS-Users] How to determine C_comp
From: Mike LaBonte (milabont@cisco.com)
Date: Thu Aug 07 2003 - 08:15:43 PDT
The HSPICE manual gives a circuit example of the Frequency Domain imaginary
current method in the Buffer Characterization section, by the way.
Mike LaBonte
-----Original Message-----
From: owner-ibis-users@eda.org [mailto:owner-ibis-users@eda.org]On Behalf Of
Muranyi, Arpad
Sent: Wednesday, August 06, 2003 4:24 PM
To: ibis-users@eda.org
Subject: RE: [IBIS-Users] How to determine C_comp
I know of about six methods to measure C_comp:
•RC time constant with a step function
•does not show voltage or frequency dependencies
•Time Domain forced saw tooth voltage
•can provide voltage dependent capacitance curves
•does not show frequency dependence
•TDR technique (Time Domain)
•does not show voltage or frequency dependencies
•Frequency Domain sweep with tank circuit
•can provide voltage dependent capacitance curves
•does not show frequency dependence(?)
•Frequency Domain imaginary current
•can provide voltage and frequency dependent capacitance curves
•shows frequency dependence very well
•Frequency Domain pole/zero method
•See BIRD 79 on IBIS web page for details
Arpad Muranyi
Intel Corporation
================================================
-----Original Message-----
From: erik.van.der.ven@philips.com [mailto:erik.van.der.ven@philips.com]
Sent: Wednesday, August 06, 2003 2:25 AM
To: ibis-users@eda.org
Cc: cor.duijndam@philips.com
Subject: [IBIS-Users] How to determine Ccomp
Dear IBIS collegues,
What is the best way to determine Ccomp?
Basically there are two ways: applying a ramp to the output terminal and
calculate Ccomp from the slew-rate, or connecting an inductor to the output
and calculate the Ccomp from the resonace frequency.
Which method gives the best results? > always, or application dependent?
How is this done for differential outputs. Outputs like LVDS have internal
feedback loops to control the common level. Must something be done with the
"other" output? Is the peaking a reliable measure for the value of Ccomp, or
may the added inductor shift the poles and zeros of the feedback buffer due
this load causing a peaking that is not just the parallel connection of
Ccomp and the test inductor?
With kind regards,
Ir. Erik van der Ven
Room DB1032
Business Line Networking Infrastructure
Philips Semiconductors BV
Gerstweg 2
6534 AE Nijmegen
The Netherlands
Phone: +31-24-3534334
|------------------------------------------------------------------
|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
This archive was generated by hypermail 2b28 : Thu Aug 07 2003 - 08:18:50 PDT