Hello Vaibhav,
my opinion is: about ISSO currents you should know the shapes
of the expected curves (more or less) and then you could check that:
ISSO_PD(V=0) = Ipulldown(V=VCC) and ISSO_PU(V=0) = Ipullup(V=VCC) .
For extraction of ISSO, I think you can use both circuits (with or without
external source),
but you must consider the Shift in voltage of the output Current when you add
external source.
I hope this is helpful,
Regards,
Fabio
From: ibis-bounce@xxxxxxxxxxxxx [mailto:ibis-bounce@xxxxxxxxxxxxx] On Behalf Of ;
Vaibhav R Katkar
Sent: Wednesday, August 28, 2019 2:51 PM
To: ibis@xxxxxxxxxxxxx; ibis-users@xxxxxxxxxxxxx
Subject: [ibis] Query on ISSO_PU, ISSO_PD and Composite Current
Hi All,
I am working on power aware feature of IBIS 5.0 and have a couple of queries
regarding the extraction process and validation as mentioned below:
1. How to validate the power aware feature (ISSO_PU, ISSO_PD and Composite
current) of IBIS 5.0?
2. For ISSO_PU and ISSO_PD extraction, do we need to sweep the power supply and
ground directly or should we use the external source in between PU circuit and
power supply for ISSO_PU extraction and between PD circuit and ground for
ISSO_PD extraction as mentioned in the IBIS specification document? Will this
sweep affect the pre-drivers?
[image.png]
3. Is the polarity of Vtable (Negative terminal connected to the VCC) for
ISSO_PU extraction correct in the below diagram from IBIS specification or
should it be same as that of Vtable of Pullup data, where positive terminal of
Vtable will be connected to the VCC( Vtable = Vcc - Voutput)?
[image.png]
Thanks in advance.
Regards,
Vaibhav