[time-nuts] The Trapezoidal Clocking
Bob Camp
kb8tq at n1k.org
Mon Dec 15 12:38:08 UTC 2014
Hi
If you treat it as a sine, you certainly get further. There are some neat sine wave input chips. The next layer to the problem is that the trapezoid may be slower than (or faster than ) a sine wave depending on just what’s going on with the system. That will make it a bit difficult to know what sort of a clock you have at each tap.
Bob
> On Dec 14, 2014, at 10:40 PM, Magnus Danielson <magnus at rubidium.dyndns.org> wrote:
>
> Hi,
>
> Agree. It's not ideal. In it's simplicity it achieves first degree delay compensation, but it is not the best of signals you get.
>
> You need to treat the signal as being essentially a sine, and overcome the slew-rate.
>
> It may be a useful technique besides it's limits.
>
> Cheers,
> Magnus
>
> On 12/15/2014 03:45 AM, Bob Camp wrote:
>> Hi
>>
>>
>> …. but …
>>
>>
>> Low edge speeds => poor signal to noise => high jitter.
>>
>> The result is a clock that aligns, but has high(er) jitter compared to a conventional square wave clock. Most of the “lower phase noise / lower jitter” progress in CMOS logic has gone hand in hand with faster edge rates.
>>
>> Bob
>>
>>
>>> On Dec 14, 2014, at 8:27 PM, Magnus Danielson <magnus at rubidium.dyndns.org> wrote:
>>>
>>> Bob,
>>>
>>> On 12/14/2014 02:10 AM, Robert Darby wrote:
>>>> This is an paper that may be of some interest to those interested in
>>>> clock distribution. The author, Jinyuan Wu has done considerable work
>>>> on FPGA TIC's with Fermi Lab.
>>>>
>>>> http://www-ppd.fnal.gov/EEDOffice-w/Projects/ckm/comadc/TrapezCLK1b.pdf
>>>
>>> How incredibly cunning!
>>>
>>> Cheers,
>>> Magnus
>>> _______________________________________________
>>> time-nuts mailing list -- time-nuts at febo.com
>>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
More information about the Time-nuts_lists.febo.com
mailing list