RE: [IBIS-Users] 3.3V I/O, 5V tolerant

From: Tom Dagostino <tom_at_.....> Date: Sat Dec 17 2005 - 16:53:10 PST · This archive was generated by hypermail 2.1.8 : Sat Dec 17 2005 - 16:57:13 PST

I'd change it to:

Voltage Ref: 5.0 4.5 5.5
Pulldown Ref: 0 0 0
Pullup Ref: 3.3 3.0 3.6
Power Clamp Ref: 5.0 4.5 5.5
GND Clamp Ref: 0 0 0

Tom Dagostino
Teraspeed(R) Labs
13610 SW Harness Lane
Beaverton, OR 97008
503-430-1065
tom@teraspeed.com
www.teraspeed.com

Teraspeed Consulting Group LLC
121 North River Drive
Narragansett, RI 02882
401-284-1827

-----Original Message-----
From: owner-ibis-users@eda.org [mailto:owner-ibis-users@eda.org]On
Behalf Of Abril, Giovanni (Space Technology)
Sent: Saturday, December 17, 2005 12:54 PM
To: ibis-users@eda.org
Subject: [IBIS-Users] 3.3V I/O, 5V tolerant

Hello IBIS experts,

I'm creating a model from HSPICE using S2IBIS2 vers. 2.1 and have a
question.

If my buffer is 3.3V i/o, but is 5V tolerant, and am using:

Voltage Ref: 3.3 3.0 3.6
Pulldown Ref: 5.0 4.5 5.5
Pullup Ref: 0 0 0
Power Clamp Ref: 5.0 4.5 5.5
GND Clamp Ref: 0 0 0

I was thinking this should vary my voltages from -5V to 10V for the clamps,
but it does not.  It instead varies from -Vcc to 2Vcc as usual.

Is this how I should be setting this up?

Thanks,
Gio

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