[ibis-quality] AW: Proposed topic of discussion
- From: "Lenski, Eckhard (NSN - DE/Munich)" <eckhard.lenski@xxxxxxx>
- To: <ibis-quality@xxxxxxxxxxxxx>
- Date: Tue, 29 Jan 2008 09:06:07 +0100
Hello David,
from my point of view you are right.
Vinl and vinh are worst case in datasheet.
But that is why we (NSN ) are putting more realistic values in the models (
like the params from micron or xilinx )
First these parameters vinl and vinh are for the whole datasheet range (
normaly vcc +-10% )
The models we are using are at vcc +-5%.
So if we would use datasheet parameters, we would do to much worst case
simulations
( e.g. propagation delays from driver out to receiver in ( for a simple
point-to-point connection ) would result in
timing form driver to receiver:
REC vinl 0.8V : 2.1ns
REC vinh 2.0V : 2.8ns
using more realistic params
REC vinl 1.0V : 2.4ns
REC vinh1.8V : 2.7ns
so I will win 300ps / 100ps )
please see attached picture
Mit freundlichen Grüßen / Best regards / Cordiali saluti / ystävällisin
terveisin
Eckhard Lenski
Nokia Siemens Networks GmbH & Co. KG
COO RA RD BTS HW GERAN BTS&NB&CP Dev SDE
CAE libraries and models
Balanstr. 59
81541 München
Germany
phone : +49 89 636 79002
fax : +49 89 636 78895
email: eckhard.lenski@xxxxxxx
Nokia Siemens Networks GmbH & Co. KG
Sitz der Gesellschaft: München / Registered office: Munich
Registergericht: München / Commercial registry: Munich, HRA 88537
WEEE-Reg.-Nr.: DE 52984304
Persönlich haftende Gesellschafterin / General Partner: Nokia Siemens Networks
Management GmbH
Geschäftsleitung / Board of Directors: Lydia Sommer, Olaf Horsthemke
Vorsitzender des Aufsichtsrats / Chairman of supervisory board: Lauri Kivinen
Sitz der Gesellschaft: München / Registered office: Munich
Registergericht: München / Commercial registry: Munich, HRB 163416
________________________________
Von: ibis-quality-bounce@xxxxxxxxxxxxx
[mailto:ibis-quality-bounce@xxxxxxxxxxxxx] Im Auftrag von ext David Banas
Gesendet: Montag, 28. Januar 2008 19:29
An: ibis-quality@xxxxxxxxxxxxx
Betreff: [ibis-quality] Proposed topic of discussion
Hi all,
I would like to propose the following topic of discussion for one of our
meetings:
Are the Vinl/Vinh values given in the [Model] section of an IBIS model supposed
to represent the worst case input switching limits, over the full range of
legal operating conditions? That is, should:
* Vinl be the lowest value ever required at the input to switch the gate
low, and
* Vinh be the highest voltage ever required to switch the gate high?
If so, then should it ever be allowed that the range of values given for these
two parameters in the [Model Spec] section extend below/above these values,
respectively? Currently, they do in both Micron and Xilinx models, and I'm
wondering if this is correct:
Xilinx
[Model] LVCMOS33_F_2
Model_type I/O
Polarity Non-Inverting
Enable Active-Low
Vinl = 0.76
Vinh = 2.2
Vmeas = 1.6500V
Cref = 0.0F
Rref = 1.0000M
Vref = 0.0V
C_comp 6.0000pF 6.0000pF 6.0000pF
[Model Spec]
Vinl 0.76 0.69 0.8
Vinh 2.2 2.0 2.3
Micron
[Model] DQ_FULL_667
Model_type I/O
|
Vinl = 700.000mV
Vinh = 1.100V
Vmeas = 900.000mV
Vref = 900.000mV
Cref = 0.0pF
Rref = 25.000Ohm
|
| typ min max
|
C_comp 2.830pF 2.400pF 3.250pF
|
[Model Spec]
| Input threshold voltage corners
Vinl 0.700V 0.650V 0.750V
Vinh 1.100V 1.050V 1.150V
Thanks,
David Banas, Sr. Staff Applications Engineer
Advanced Products Division
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