[IBIS-Users] RE: Question about differential pair buffer

Ramiro,

In that case, your IBIS model should contain a [Pulldown]
[GND Clamp] and a [POWER Clamp] I-V table.  The resistors
on the top and any clamping currents above Vcc should be
put into the [POWER Clamp] table, the transistor's current
minus the 3-stated current (including any clamping and the
resistors) should go into the [Pulldown] table, and the
clamping currents below GND (minus the resistors on the
top) should go into the [GND Clamp] table.  Be careful 
not to double count for any of these in the various tables.

The pullup and power clamp data must be "Vcc relative",
that is the source you sweep with is connected between
the output pad and Vcc.

I hope this helps to answer your questions.

Arpad
**********************************************************

-----Original Message-----
From: RODRIGUEZ_LECONA_RAMIRO [mailto:rlecona@siu.buap.mx] 
Sent: Tuesday, June 07, 2005 5:16 AM
To: Muranyi, Arpad
Cc: ibis-info@eda.org; ibis-users@eda.org
Subject: Re: Question about differential pair buffer


   Hi Arpad,

      My question is related to the pullup I-V curve, and the differential 
pair is not an open collector device. It has a load that consists of a pair 
of resistors. Also, I have another question: If I want to extract the pullup 
I-V curve, Do I have to connect the dc voltage source (the voltage source 
that sweeps from -Vcc to 2Vcc) between one of the outputs and Vdd or Vos? 

     Best Regards, 

     Ramiro

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