Re: [IBIS-Users] Waveform mismatch question


Subject: Re: [IBIS-Users] Waveform mismatch question
From: Duane Mattheisen (duane.mattheisen@onsemi.com)
Date: Thu Jan 23 2003 - 12:17:39 PST


John Take out as much fixture resistance as possible in the DC
measurement.
  Also for the AC measurement put a big capacitor (0.1uf and a >2.2uF
tantalum cap) to ground on the Rfixture having the other side of the
Rfixture that connects to the output as close as possible to the
output.
                                    Sincerely Duane Mattheisen
"Angulo, John" wrote:
>
> The following is posted on behalf of John Phillippe at Motorola. Please send any private replies to john.phillippe@motorola.com only.
>
> --------------------------------------------------
>
> Ibis Guru's,
> I get quite a few waveform mismatches between the rising/falling
> edges and the I/V curves like the one shown below.
>
> WARNING - Model pad_26v_fast: The [Falling Waveform]
> with [R_fixture]=50 Ohms and [V_fixture_max]=0V
> has MAX column DC endpoints of 0.05V and 1.75v, but
> an equivalent load applied to the model's I-V tables yields
> different voltages ( 0.16V and 1.91V),
> a difference of 6.66% and 8.94%, respectively.
>
> I'm curious if this is a common problem, or if there are some simple
> solutions to get everything to match up. I check the waveforms and set
> the sim time long enough to make sure the waveforms are stable. Any
> help/suggestions would be greatly appreciated.
>
> --
> John Phillippe
> SPS, 32 Bit Embedded Controller Division, IC Creation
> Motorola - 512-895-1835
> Austin, TX - john.phillippe@motorola.com
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