[SOLVED] ibis_buffer problems with [Series Pin Mapping] keyword

[shreyaskm]

Hello all,

I am trying to use ibis_buffer found in the analogLib library by cadence.
i am connecting a differential resistance of 100 ohm between two
input pins defined by [Pin] of two different [Models] by using [Series Pin Mapping] keyword.

This is how i have added the series resistance:-

[Series Pin Mapping] pin_2 model_name function_table_group
1 2 R_term
3 4 R_term
[Model] R_term
Model_type Series
Polarity Non-Inverting
C_comp 0pF 0pF 0pF
[Temperature Range] 25 85 -40
[Voltage Range] 1.8 1.65 1.95
[R Series] 100ohm 90ohm 110ohm

This is passing the IBIS_parser but somehow the resistance between two [Pin]s is not getting detected.

Could somebody suggest me how to proceed?
I have two questions:-
1. Is ibis_buffer capable of identifying this series resistance?
2. Is there anything missing in the way I am inserting the series resistance?

Thanks,
Shreyas

 

[b00merang]

Hello shreyaskm,

The way you're defining the serie_resistance below appears fine. I'm not sure why Cadence is not detecting it. I would suggest placing a physical 100ohm resistor across your circuit in place of your model and see what you get. At the very least, this will confirm that the simulator is or isn't catching the serie_resistance in your model.

Also, are Pins 1,2,3,4 previously defined somewhere in your model as diff pins? ...in case they're not, also try defining them as such and see what you get.

Regards,