Re: [time-nuts] Yet another GPSDO - locking to 10MHz
Hi Murray, Why did you use such a large division factor - or any for that matter? Could you not just have used a PLL with very long time constant running at 10 MHz? Peter On 27 June 2010 20:14, Murray Greenman murray.green...@rakon.com wrote: I have a design which locks a high performance 10MHz OCXO to a 10MHz source which should work equally well with the LEA5, or any source of 5 or 10MHz. I designed it for use with a distributed factory GPS reference which has picked up noise, hum and phase modulation, in order to deliver a high quality but GPS locked reference direct to equipment. The design adds nearly three orders of improvement. Essentially it divides the incoming 10MHz by 16384 and compared the phase with a similar division from the OCXO, within an ATTiny2313 micro. The phase detector is a D-flip-flop type implemented in software (in interrupts), and it delivers a locked reference with ADev around 10e-12 for Tau between 1s and 20s. The micro also keeps a real time clock and does various background monitoring and telemetry tasks. There is PC monitoring software as well. There are only four chips in the design. While I can't share the code (belongs to my employer), the idea is simple enough and I could share the schematic. Eight of these units have been built. I used the excellent Rakon STP2402E OCXO. Regards, Murray Greenman ZL1BPU ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Yet another GPSDO - locking to 10MHz
On Sun, 27 Jun 2010 20:59:51 -0400 Robert Benward rbenw...@verizon.net wrote: All this talk about interpolation reminds me of a little neat chip by Analog Devices, AD9500. It's programmable digital delay, bit, with lops resolution with a loons full-scale range. I believe (from app notes) you can push it to 100us FS, giving 390ns resolution. I think the minimum jitter at the lowest FS was about lops. The AD9500 is cell and the 9501 is TTS. Unfortunately, the AD9500 line is obsolete with no replacement. Which means it will be quite soon not available anymore. Attila Kinali -- If you want to walk fast, walk alone. If you want to walk far, walk together. -- African proverb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Yet another GPSDO - locking to 10MHz
Unfortunately, the AD9500 line is obsolete with no replacement. Which means it will be quite soon not available anymore. On-Semi makes a programmable delay: MC100EP195, 2.2 to 12.2 ns in 10 ps steps There are a couple of other similar chips. http://www.onsemi.com/PowerSolutions/parametrics.do?id=586 -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Yet another GPSDO - locking to 10MHz
I have a design which locks a high performance 10MHz OCXO to a 10MHz source which should work equally well with the LEA5, or any source of 5 or 10MHz. I designed it for use with a distributed factory GPS reference which has picked up noise, hum and phase modulation, in order to deliver a high quality but GPS locked reference direct to equipment. The design adds nearly three orders of improvement. Essentially it divides the incoming 10MHz by 16384 and compared the phase with a similar division from the OCXO, within an ATTiny2313 micro. The phase detector is a D-flip-flop type implemented in software (in interrupts), and it delivers a locked reference with ADev around 10e-12 for Tau between 1s and 20s. The micro also keeps a real time clock and does various background monitoring and telemetry tasks. There is PC monitoring software as well. There are only four chips in the design. While I can't share the code (belongs to my employer), the idea is simple enough and I could share the schematic. Eight of these units have been built. I used the excellent Rakon STP2402E OCXO. Regards, Murray Greenman ZL1BPU ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Yet another GPSDO - locking to 10MHz
All this talk about interpolation reminds me of a little neat chip by Analog Devices, AD9500. It's programmable digital delay, bit, with lops resolution with a loons full-scale range. I believe (from app notes) you can push it to 100us FS, giving 390ns resolution. I think the minimum jitter at the lowest FS was about lops. The AD9500 is cell and the 9501 is TTS. http://pdf1.alldatasheet.com/datasheet-pdf/view/48545/AD/AD9500.html app note http://www.analog.com/static/imported-files/application_notes/105895411AN-260.pdf Bob - Original Message - From: Murray Greenman To: time-nuts@febo.com Sent: Sunday, June 27, 2010 3:14 PM Subject: [time-nuts] Yet another GPSDO - locking to 10MHz I have a design which locks a high performance 10MHz OCXO to a 10MHz source which should work equally well with the LEA5, or any source of 5 or 10MHz. I designed it for use with a distributed factory GPS reference which has picked up noise, hum and phase modulation, in order to deliver a high quality but GPS locked reference direct to equipment. The design adds nearly three orders of improvement. Essentially it divides the incoming 10MHz by 16384 and compared the phase with a similar division from the OCXO, within an ATTiny2313 micro. The phase detector is a D-flip-flop type implemented in software (in interrupts), and it delivers a locked reference with ADev around 10e-12 for Tau between 1s and 20s. The micro also keeps a real time clock and does various background monitoring and telemetry tasks. There is PC monitoring software as well. There are only four chips in the design. While I can't share the code (belongs to my employer), the idea is simple enough and I could share the schematic. Eight of these units have been built. I used the excellent Rakon STP2402E OCXO. Regards, Murray Greenman ZL1BPU ___ time-nuts mailing list -- time-nuts@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@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
