:Clock Dithering - some more information
I followed the recent discussion threads on this topic, but it is not in my
main stream of interest. However, I just remembered an extensive report I
had seen on the subject.
The report is Investigation into possible effects resulting from dithered
purposes by TV broadcasts with a 4 MHz channel
bandwidth, the dithering may not take the signal outside the bandpass at
all, and the dithering may actually cause more interference effect than if
the signal was purely cw (this last purely conjecture on my part, but very
easy to measure per one of my
3b10ff0a008ff6458711e6e375e830412c1...@ustr-exch2.na.uis.unisys.com,
George, David L george.da...@unisys.com inimitably wrote:
What is Dithering?
The dictionary defines dithering as agitating or in a state of indecision.
Dithering is a method for distributing energy across a wider spectrum
will
be an average related to how long it spends in the passband compared to the
filter time constant. But if the frequency where the measurement is made is
used for commercial purposes by TV broadcasts with a 4 MHz channel
bandwidth, the dithering may not take the signal outside the bandpass at
all
What is Dithering?
The dictionary defines dithering as agitating or in a state of indecision.
Dithering is a method for distributing energy across a wider spectrum.
Another and more accurate term for dithering is spread spectrum. In a
spread spectrum application the clock frequency or carrier
I followed the recent discussion threads on this topic, but it is not in my
main stream of interest. However, I just remembered an extensive report I
had seen on the subject.
The report is Investigation into possible effects resulting from dithered
clock oscillators on EMC measurements and
tkrepdavsml7e...@jmwa.demon.co.uk, John Woodgate
j...@jmwa.demon.co.uk inimitably wrote:
4.3.2.7.2.20010618143751.00b3d...@box.tin.it, Paolo Roncone
paolo...@tin.it inimitably wrote:
As for interference to broadband receivers (like TV equipment) I remember a
Lexmark study published a few years
200106182001.qaa14...@interlock2.lexmark.com, rogle...@lexmark.com
inimitably wrote:
According to our extensive tests in conjunction with
Philips Consumer Electronics, digital TV (both COFDM
and ATSC) is actually less susceptible to interference
from spread spectrum clocks (ssc) than current
4.3.2.7.2.20010618143751.00b3d...@box.tin.it, Paolo Roncone
paolo...@tin.it inimitably wrote:
As for interference to broadband receivers (like TV equipment) I remember a
Lexmark study published a few years ago that showed no increased
interference from modulated clocks vs unmodulated clocks
@interlock.lexmark.com
cc:(bcc: Rob A Oglesbee/Lex/Lexmark)
Subject: Clock dithering
3b2a4fda.8c64c...@mediaone.net, David Heald davehe...@mediaone.net
inimitably wrote:
Con's? None that I can think of, but...I have seen somewhere (maybe
here??) that the EU is considering new regulations for modulated
Hi Cyril,
I have a very good (EMC-wise) experience with clock dithering.
I started using the Spread Spectrum Clock Generation (SSCG) technique
(patented by Lexmark) in 1995 when I worked for my previous company.
We made printers and one of our main customers was IBM. They pushed us to
use
Hi Cyril,
I have a very good (EMC-wise) experience with clock dithering.
I started using the Spread Spectrum Clock Generation (SSCG) technique
(patented by Lexmark) in 1995 when I worked for my previous company.
We made printers and one of our main customers was IBM. They pushed us to
use
wrote:
Hi Ken:
In conclusion, dithering will help you meet a test requirement, but it might
not actually reduce potential interferences.
I have come to the same qualitative conclusion,
and the EMC experts with whom I have discussed
this concept agree.
But, is there any evidence
A
Sent: Friday, June 15, 2001 8:16 PM
To: emc-pstc
Cc: McBride, James; Davis, Brett A.; Wismer, Sam; Massey, Doug C.
Subject: Clock dithering
Resending due to no subject listed in first e-mail.
-Original Message-
From: Binnom, Cyril A
Sent: Friday, June 15, 2001 10:14 AM
3b2a4fda.8c64c...@mediaone.net, David Heald davehe...@mediaone.net
inimitably wrote:
Con's? None that I can think of, but...I have seen somewhere (maybe
here??) that the EU is considering new regulations for modulated clocks,
but this is in the early stages, so use them now while you can get
Resending due to no subject listed in first e-mail.
-Original Message-
From: Binnom, Cyril A
Sent: Friday, June 15, 2001 10:14 AM
To: 'emc-pstc'
Cc: McBride, James; Wismer, Sam; Massey, Doug C.; Davis, Brett A.
Subject:
Group,
I am experiencing a EMI
Hi Ken:
In conclusion, dithering will help you meet a test requirement, but it might
not actually reduce potential interferences.
I have come to the same qualitative conclusion,
and the EMC experts with whom I have discussed
this concept agree.
But, is there any evidence, anecdotal
Be careful. IBM (perhaps Lexmark now) holds a patent on certain aspects of
this technology.
Richard Woods
--
From: Binnom, Cyril A [SMTP:binno...@ems-t.com]
Sent: Friday, June 15, 2001 10:07 AM
To: emc-pstc
Cc: McBride, James; Wismer, Sam;
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