Re: problem with a model

Hi Olli.

In case you are using the s2ibis software it seems that you are
not using the correct version.
There is a fix that increases the resolution to 4 decimal points.
This is very important in pullup/pulldown curve which are
manipulated (curve reduction) by the s2ibis software.

The fix might do wonders to solve this issue.

However, another tip might be is to gently fine tune your Vinh/Vinl like:
[vil] 0.6 0.6 0.5
[vih] 1.6 1.6 1.6

This method did solve a lot of problems.

Also in case you are using Hspice I recommend removing ALL .options from
the spice file. You might be increasing the error tolerance to get
convergence.
Doing so will give such results.

For more tips and ideas you are welcome to contact me.

Olli Timonen wrote:

> Hi!
>
> I have a problem with one IBIS model. The current of a pulldown starts
> to decrease after about 5V. How is this possible? What causes this kind
> of occurrences and is there any kind of solutions to fix this kind of a
> model?
>
> The [Pulldown] of a model in question is below.
>
> Regards,
> Olli
>
> |************************************************************************
>
> | Model Buffer
> |************************************************************************
>
> |
> [Model] Buffer
> Model_type 3-state
> Polarity Non-Inverting
> Enable Active-High
> Vinl = 0.00V
> Vinh = 5.00V
> C_comp 5.00pF 5.00pF 5.00pF
> |
> |
> [Temperature Range] 25.00 100.00 -40.00
>
> [Voltage Range] 5.00V 4.50V 5.50V
> [Pulldown]
> | voltage I(typ) I(min) I(max)
> |
> -5.00 -1000.00uA -1000.00uA 0.00A
> -4.60 0.00A 0.00A 0.00A
> -4.20 -1.00mA -1.00mA -1000.00uA
> -3.80 -1.00mA 0.00A -1.00mA
> -3.40 -1.00mA 0.00A -1.00mA
> -3.00 -1000.00uA -1000.00uA -1.00mA
> -2.60 -1000.00uA -1000.00uA -2.00mA
> -2.20 -1.00mA 0.00A -2.00mA
> -1.80 -2.00mA -2.00mA -3.00mA
> -1.40 -3.50mA -2.00mA -5.80mA
> -1.00 -10.70mA -4.60mA -37.60mA
> -0.90 -19.70mA -6.50mA -83.83mA
> -0.80 -43.09mA -10.50mA -93.72mA
> -0.70 -53.81mA -20.14mA -85.15mA
> -0.60 -48.13mA -28.69mA -75.24mA
> -0.50 -41.67mA -26.51mA -65.04mA
> -0.40 -34.83mA -22.15mA -54.70mA
> -0.30 -27.32mA -17.29mA -43.21mA
> -0.20 -19.06mA -12.00mA -30.38mA
> -0.10 -10.00mA -6.25mA -16.04mA
> 0.00 0.00A 0.00A 0.00A
> 0.10 10.61mA 6.62mA 16.95mA
> 0.20 21.06mA 13.28mA 33.15mA
> 0.30 31.04mA 19.69mA 48.53mA
> 0.40 40.58mA 25.83mA 63.11mA
> 0.50 49.67mA 31.71mA 76.92mA
> 0.60 58.31mA 37.32mA 89.97mA
> 0.70 66.54mA 42.66mA 102.32mA
> 0.80 74.33mA 47.74mA 113.91mA
> 0.90 81.73mA 52.57mA 124.89mA
> 1.00 88.71mA 57.14mA 135.18mA
> 1.10 95.29mA 61.45mA 144.77mA
> 1.20 101.53mA 65.51mA 153.85mA
> 1.30 107.31mA 69.32mA 162.24mA
> 1.40 112.70mA 72.88mA 170.12mA
> 1.50 117.78mA 76.19mA 177.41mA
> 1.60 122.47mA 79.26mA 184.09mA
> 1.70 126.85mA 82.09mA 190.38mA
> 1.80 130.83mA 84.68mA 196.06mA
> 1.90 134.52mA 87.04mA 201.25mA
> 2.00 137.90mA 89.16mA 206.03mA
> 2.10 140.89mA 91.06mA 210.31mA
> 2.20 143.57mA 92.73mA 214.20mA
> 2.30 145.95mA 94.18mA 217.58mA
> 2.40 148.04mA 95.40mA 220.56mA
> 2.50 149.82mA 96.42mA 223.14mA
> 2.60 151.30mA 97.23mA 225.32mA
> 2.70 152.48mA 97.82mA 227.11mA
> 2.80 153.47mA 98.21mA 228.59mA
> 2.90 154.15mA 98.50mA 229.67mA
> 3.00 154.53mA 98.79mA 230.45mA
> 3.10 155.01mA 99.06mA 231.03mA
> 3.20 155.29mA 99.28mA 231.51mA
> 3.30 155.68mA 99.57mA 231.99mA
> 3.40 156.06mA 99.85mA 232.46mA
> 3.50 156.34mA 100.04mA 232.84mA
> 3.60 156.62mA 100.23mA 233.32mA
> 3.70 156.90mA 100.41mA 233.70mA
> 3.80 157.18mA 100.60mA 233.98mA
> 3.90 157.46mA 100.79mA 234.35mA
> 4.00 157.64mA 100.97mA 234.63mA
> 4.10 157.92mA 101.16mA 234.91mA
> 4.20 158.11mA 101.35mA 235.09mA
> 4.30 158.29mA 101.43mA 235.36mA
> 4.40 158.47mA 101.62mA 235.54mA
> 4.50 158.55mA 101.70mA 235.71mA
> 4.60 158.73mA 101.79mA 235.79mA
> 4.70 158.81mA 101.88mA 235.87mA
> 4.80 158.89mA 101.96mA 235.94mA
> 4.90 158.97mA 102.08mA 236.02mA
> 5.00 159.05mA 101.98mA 236.09mA
> 5.10 159.03mA 101.88mA 236.07mA
> 5.20 159.01mA 102.00mA 236.04mA
> 5.30 159.09mA 102.10mA 235.91mA
> 5.40 159.04mA 102.20mA 235.89mA
> 5.50 158.73mA 102.10mA 235.76mA
> 5.60 158.13mA 102.20mA 235.64mA
> 5.70 157.92mA 102.20mA 235.41mA
> 5.80 158.36mA 101.80mA 235.28mA
> 5.90 158.40mA 102.00mA 234.97mA
> 6.00 158.40mA 102.00mA 234.25mA
> 6.40 157.60mA 102.00mA 232.97mA
> 6.80 158.00mA 102.00mA 232.20mA
> 7.20 156.00mA 101.00mA 231.00mA
> 7.60 156.00mA 101.00mA 230.00mA
> 8.00 155.00mA 101.00mA 229.00mA
> 8.40 155.00mA 101.00mA 228.00mA
> 8.80 155.00mA 101.00mA 226.00mA
> 9.20 154.00mA 100.00mA 225.00mA
> 9.60 153.00mA 100.00mA 224.00mA
> 10.00 153.00mA 99.00mA 222.00mA

--
                \\|//
                (o o)
~~~~~~~~~~~~oOOo~(_)~oOOo~~~~~~~~~~~~~~~~~~~
Dan Aleksandrowicz
Galileo Technology
Mercaz Ofek 1   (Building B')
Northern Industrial Zone, LOD 71293,  ISRAEL
email:dan@galileo.co.il
Tel: +972 8 9247555    (-
     Ext. 324         |__|
                      |__|
                     #|oo| |--|   ___
           _  _    |--|  | |  |\ |oo|)        /\
       __  \\ \\   |------------\| #|--\     _||-
   ____\ \__\\_\\__|_||_________________\___|   |__v-___
   \                                                   /
    \      "Smoke on the water. Fire in the sky."     /
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~