Re: Process parameters

Hello Vipul,

Since we create our IBIS models from SPICE data, we would use
"typ", "min", "max" process parameters if we have them all.
Usually, the customers require us to have all the process-
variation corners in the model.

So I think the cookbook can include the case of "min", and "max"
as well as "typ".

Regards,

Hoang Nguyen
Mitsubishi Semiconductor America, Inc.

> From owner-ibis@server.vhdl.org Wed Jul 16 05:50:44 1997
> Date: Wed, 16 Jul 1997 03:48:15 -0500
> From: Vipul Singhal <vkumar@india.ti.com>
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> Cc: sram@india.ti.com, vkumar@india.ti.com, ngs@india.ti.com
> Subject: Process parameters
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>
> Hello all,
>
> I have a doubt regarding the method for obtaining the curves
> by simulation as outlined in IBIS COOKBOOK. The cookbook says ( under
> the section 3.3.1 : "OBTAINING CURVES BY SIMULATION - Simulation
> Specifics" ) that :
>
> "For both the rise/fall time and I-V curve measurements,
> use "typical" process parameters."
>
> "For CMOS:
> min = min VCC, max temperature, typ process parameters
> ---
> max = max VCC, min temperature, typ process parameters"
> ---
>
> Later it says that " To account for process variation, decrease the
> current values taken at min conditions, increase the current values
> taken at max, and derate the rise and fall time values by the
> appropriate percentages. "
>
> This seems to be a roundabout way of doing it. Why can't we
> directly use "typ" , "min" , and "max" process parameters, as
> appropriate, directly in the simulations ? For example, if SPICE is
> used for simulation, we can have three different SPICE models for
> transistors, corresponding to the process-variation corners. Why
> should "typical" be used in each case ?
>
> Regards,
> Vipul K. Singhal
> Texas Instruments
>
>
 
Received on Wed Jul 16 05:48:00 1997