> However it does discipline the DDS outputs as intended. > It is somewhat akin to Ulrich's approach perhaps without the > robust outlier rejection.
Surely AD has not copied from me, but yes indeed this looks similar to my approach. The output noise may by tamed by loosely coupling a high quality OCXO to the output. Perhaps one should think over a circuit that a) surpresses PPS outliers and b) applies sawtooth correction to the PPS Best regads Ulrich Bangert > -----Ursprüngliche Nachricht----- > Von: [email protected] > [mailto:[email protected]] Im Auftrag von Bruce Griffiths > Gesendet: Donnerstag, 11. Juni 2009 07:42 > An: [email protected]; Discussion of precise time and > frequency measurement > Betreff: Re: [time-nuts] AD9548 - Clock IC Generates Up to > 400 MHz from 1 PPSGPS Signal > > > However it does discipline the DDS outputs as intended. > It is somewhat akin to Ulrich's approach perhaps without the > robust outlier rejection. This approach would allow a wide > range of relatively stable low noise sources to be used > including those that may have drifted out of adjustment > range. One drawback for some applications is the relatively > high phase noise floor. > > Bruce > > Lester Veenstra wrote: > > Sync to 1 pps but will not discipline the frequency source > > > > > > Lester B Veenstra MØYCM K1YCM > > [email protected] > > [email protected] > > [email protected] > > > > > > US Postal Address: > > PSC 45 Box 781 > > APO AE 09468 USA > > > > UK Postal Address: > > Dawn Cottage > > Norwood, Harrogate > > HG3 1SD, UK > > > > Telephones: > > Office: +44-(0)1423-846-385 > > Home: +44-(0)1943-880-963 > > Guam Cell: +1-671-788-5654 > > UK Cell: +44-(0)7716-298-224 > > US Cell: +1-240-425-7335 > > Jamaica: +1-876-352-7504 > > > > This e-mail and any documents attached hereto contain > confidential or > > privileged information. The information is intended to be > for use only > > by the individual or entity to whom they are addressed. If > you are not > > the intended recipient or the person responsible for delivering the > > e-mail to the intended recipient, be aware that any disclosure, > > copying, distribution or use of the contents of this e-mail or any > > documents attached hereto is prohibited. > > > > -----Original Message----- > > From: [email protected] > [mailto:[email protected]] > > On Behalf Of christopher hoover > > Sent: Thursday, June 11, 2009 5:26 AM > > To: [email protected] > > Subject: [time-nuts] AD9548 - Clock IC Generates Up to 400 > MHz from 1 > > PPSGPS Signal > > > > > > [fyi -- this may be of general interest, but n.b. that this A.D. > > marketing - ch] > > > > > > Clock IC Generates Up to 400 MHz from 1 PPS GPS Signal > > > > The AD9548 > > > <http://www.analog.com/en/clock-and-timing/clock-generation-an d-distribution > /ad9548/products/product.html> > is the first clock chip in the industry to directly generate up to a 400 > MHz output clock, with extremely low phase noise, that is locked to a > standard one pulse-per-second (PPS) GPS clock signal. This performance > is a result of combining Analog Devices' proprietary direct digital > synthesis (DDS) technology with a state-of-the-art digital phase-locked > loop (DPLL). Other solutions for synchronizing to the GPS 1 PPS source > typically rely on one or more frequency upconversion steps. Maintaining > low output noise, while providing over eight orders of magnitude of > frequency scaling (1 Hz input to over 100 MHz output), is a significant > challenge. The AD9548 is able to mitigate this effect thanks to a > digital loop filter capable of bandwidths as low as 1 MHz (10 Hz to 3 Hz). > > > / > / > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
