Hi Mike,
Thanks a lot for your reply.i get confused after your reply.
My Thoughts was that we need to get PULLDN data in the range from (-0.4V
to 0.8V) as that will be the voltage on transmission line.
i was using *V_fixture=0.4V* in [Rising waveform] . Will it be right to use
*V_fixture=1.8V* as for PULLDN data? and what will be the voltage used in
[Voltage Range] and [POWER CLAMP Reference] ?
Can u elaborate that point,please?
i have another question about the *range of voltages [-VCC - 2*VCC ]* which
should be used in TYP,MIN,MAX in gathering I-V data if my supply voltage is
[TYP,MIN,MAX]=[1.8,1.52,1.98]?
Thanks,
Ahmed
On Mon, Jan 9, 2017 at 4:41 PM, Mike LaBonte <mlabonte@xxxxxxxxxx> wrote:
Ahmed,
This is a great question, one that might trigger a discussion about
improving the clarity of the IBIS specification. The rule you refer to is
in Table 16 on page 165 of IBIS 6.1 <http://ibis.org/ver6.1/ver6_1.pdf>,
in the “NOTES ON DATA DERIVATION METHOD” section. We might need to improve
that section as part of our ongoing IBIS 6.2 update, particularly because
the table uses GND and POWER to refer to voltage values. For IBIS 6.2 we
intend to refer instead to IBIS keywords that are properly defined as
voltage values.
For the time being I would recommend extending any [Pulldown] and [Pullup]
tables using 1.8V as the basis in your specific case, even if you have to
extrapolate to get beyond 0.4V. The reason is that tools will have to sum
the tables over the full range to form the data actually simulated, and it
would be best not to make assumptions about how the tools will extrapolate
the “missing” data beyond 0.4V.
Mike
*From:* ibis-bounce@xxxxxxxxxxxxx [mailto:ibis-bounce@xxxxxxxxxxxxx] *On
Behalf Of *Ahmed Essam
*Sent:* Sunday, January 08, 2017 6:57 AM
*To:* ibis@xxxxxxxxxxxxx; ibis-users@xxxxxxxxxxxxx
*Subject:* [ibis] PullDown data Range
Hi All,
i am working on ibis model for an output buffer.The ESD devices is
connected to I/O supply equal to 1.8V .while the buffer is connected to
supply equal to 0.4V.
I defined the voltage range and power clamp reference as follows
[Voltage Range] 0.4 NA NA
[POWER Clamp Reference] 1.8 NA NA
Shall the pulldown data range be( from -0.4V to 0.8V) ? or ( from -1.8V
to 3.6V) ?
Thanks,
Ahmed
