RE: Clock Dithering - some more information

2001-06-28 Thread Chris Chileshe
: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

Re: Dithering

2001-06-22 Thread John Woodgate
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

Re: Dithering

2001-06-22 Thread John Woodgate
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

Re: Dithering

2001-06-22 Thread Ken Javor
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

RE: Dithering

2001-06-22 Thread George, David L
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

Clock Dithering - some more information

2001-06-21 Thread Jacob Schanker
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

Re: Clock dithering

2001-06-19 Thread John Woodgate
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

Re: Clock dithering

2001-06-19 Thread John Woodgate
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

Re: Clock dithering

2001-06-19 Thread John Woodgate
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

Re: Clock dithering

2001-06-18 Thread roglesbe
@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

Re: Clock dithering

2001-06-18 Thread Paolo Roncone
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

Re: Clock dithering

2001-06-18 Thread Paolo Roncone
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

Re: Dithering

2001-06-17 Thread Ken Javor
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

RE: Clock dithering

2001-06-17 Thread CE-test - Ing. Gert Gremmen - ce-marking and more...
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

Clock dithering

2001-06-16 Thread John Woodgate
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

Clock dithering

2001-06-15 Thread Binnom, Cyril A
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

Dithering

2001-06-15 Thread Rich Nute
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

RE: Clock Dithering

2001-06-15 Thread WOODS
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;