Re: [SI-LIST] : EMI

HANS_MELLBERG@NON-HP-Cupertino-om5.om.hp.com
Wed, 29 Oct 97 09:55:12 -0800

One thing to consider among other possible problems like loss of phase lock, is
that the jitter (or dithering) has to have a greater frequency jump than the
FCC's and CISPR's measurement bandwidth (BW) or you will not realize any gains
(or EMI emissions). If the jumps are smaller than the BW, the total energy in
the BW is the same! Spectrum analyzer may not have time to capture and sum the
dithering average and you may get a false lower reading. A receiver would not be
fooled so you would get the real result.
Hans

______________________________ Reply Separator _________________________________
Subject: [SI-LIST] : EMI
Author: Non-HP-manix (manix@shuttletech.co.in) at HP-ColSprings,mimegw5
Date: 10/28/97 11:38 PM

Hi,

A WEB source suggests that:-

In order to reduce EMI, there should be some logic that introduces a
jitter into the clock network. This results a pulse energy to spread
horizontally in the frequency domain which inturn results in the
quasi-peek energy reduced. This will cause the resultant average
frequency reduced slightly.

Could anybody please explain what does this mean? Will it help? If
so, where do I get more deatiled information about this?

Thanks for your attention,

Regards,
Manix Velu.

E-Mail: manix@shuttletech.co.in
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