[uunet!ccm2.jf.intel.com!Will_Hobbs: Re[3]: V/I table in Bench measurements]

Syed,

I agree that you should not try to sweep beyond what you think the part can
safely handle. I suggest you do not do the extraploation, however, as that will
not give you the control over what the customers see. Consceivably a simulator
vendor might know what he was doing and be able to extrapolate in the way
best suited for his simulator.

only partly in jest,
jonp

>Return-Path: <uunet!ccm2.jf.intel.com!Will_Hobbs>
>Date: Fri, 22 Jul 94 13:26:01 PST
>From: Will Hobbs <uunet!ccm2.jf.intel.com!Will_Hobbs>
>To:
> uunet!ichips.intel.com!speters
>Cc: uunet!tevm2.nsc.com!cjfgsc
>Subject: Re[3]: V/I table in Bench measurements

>Text item:

>Syed,

>I agree that you should not try to sweep beyond what you think the part can
>safely handle. I suggest you do the extraploation, however, as that will give
>you the control over what the customers see. Consceivably a simulator might not
>extrapolate in the way you would want, or not do so at all.

>Will Hobbs
>Intel Corp.

Hello:
        I think bench data should be taken without exceeding the ABS MAX rating
        of the device. This could mean a swing smaller than the specified
        -5V to +10V. Maybe, the simulator can extrapolate the data point to the
        desired level. I am not sure if all simulators can do that or not.

Regards,
Syed Huq
National Semiconductor

> From speters@ichips.intel.com Wed Jul 20 16:15:25 1994
> To: huq@rockie.nsc.com, ibis@vhdl.org
> Subject: Re[1]: V/I table in Bench measurements
> Date: Wed, 20 Jul 1994 15:43:59 -0700
> From: Stephen Peters <speters@ichips.intel.com>
> Content-Length: 1624
>
>
> Hello Bob, Syed:
>
> You know, Syed's question brings up an interesting point. Suppose the
> VCC of a device is at +5V but the output is TTL and the maximum swing
> is, say 3.5V. Should the output be characterises from -3.5 to 7.0v
> (the maximum voltage range that the output would ever realistically
see)
> or does one still have to do the -5 to +10v range?
>
> Best Regards,
> Stephen Peters
> Intel Corp.
>
>
>
> Syed:
>
> Here are my views on your questions:
>
> (1) The Voltage table can be presented in any order: -ve to +ve
or +ve to -ve.
> (2) The table itself must go to at least the specified limits. It is
> permissible to do the measurements over a reasonable range and then
extrapolate
> to the end points. For example, you man not want to measure below
-2V, but you
> still need to provide at least one extrapolated data point out to -5V if Vcc
> is 5V.
>
> Bob Ross,
> Interconnectix, Inc.
>
> > Hi fellow gurus:
>
> > Got two questions about the V/I table.
>
> > 1) Does the Voltage table need to ramp down from a -ve number
to a +ve or can it
> > be from +ve to -ve number as well ?
> > Ex: For [Pulldown] the Voltage table goes from -5.0V to +10.0V
>
>
> > 2) For most of the V/I table, IBIS shows that the voltage range
should go from
> > +10V to -5V. Problem is, there are devices whose I/O structure
cannot handle
> > swings that large. In that case, since we should not test a
device beyond
> > it's Absolute Recommended Operating(ABS Max) range, is it O.K
 NOT to swing
> > the I/O all the way to +10 to -5V ???
>
> > Regards,
> > Syed huq
> > National Semiconductor
>
>
>

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Subject: Re: Re[1]: V/I table in Bench measurements
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