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LB

Leo Bodnar

Thu, Nov 2, 2017 9:45 PM

This is, essentially, how modern delta-sigma DACs work while achieving 24-bit and higher precision using only a single bit converter internally and a lot of clever digital filtering.
Multiple loops are what would be called "higher order" in delta-sigma parlance.
Delta-sigma tech is not poor man's DAC - it has properties that other conversion methods can't achieve, e.g. noise shaping and trivial aliases rejection.
I suspect delta-sigma body of knowledge can be applied almost wholesale to this seemingly silly oscillator concept.
Did I just repeat something trivial that has been discussed to death here before?
Leo

From: Bob kb8tq kb8tq@n1k.org
Subject: Re: [time-nuts] Holdover, RTC for Pi as NTP GPS source
There’s no particular reason to stop at the 100:1 point. You can run multiple
loops at the same time and get out to essentially any level of precision. The
only question is over what averaging interval the precision applies.

This is, essentially, how modern delta-sigma DACs work while achieving 24-bit and higher precision using only a single bit converter internally and a lot of clever digital filtering. Multiple loops are what would be called "higher order" in delta-sigma parlance. Delta-sigma tech is not poor man's DAC - it has properties that other conversion methods can't achieve, e.g. noise shaping and trivial aliases rejection. I suspect delta-sigma body of knowledge can be applied almost wholesale to this seemingly silly oscillator concept. Did I just repeat something trivial that has been discussed to death here before? Leo > From: Bob kb8tq <kb8tq@n1k.org> > Subject: Re: [time-nuts] Holdover, RTC for Pi as NTP GPS source > There’s no particular reason to stop at the 100:1 point. You can run multiple > loops at the same time and get out to essentially any level of precision. The > only question is over what averaging interval the precision applies.

BK

Bob kb8tq

Thu, Nov 2, 2017 11:31 PM

Hi

I believe you indeed have tied this back to a number of papers ….

Bob

On Nov 2, 2017, at 5:45 PM, Leo Bodnar leo@leobodnar.com wrote:

This is, essentially, how modern delta-sigma DACs work while achieving 24-bit and higher precision using only a single bit converter internally and a lot of clever digital filtering.
Multiple loops are what would be called "higher order" in delta-sigma parlance.
Delta-sigma tech is not poor man's DAC - it has properties that other conversion methods can't achieve, e.g. noise shaping and trivial aliases rejection.
I suspect delta-sigma body of knowledge can be applied almost wholesale to this seemingly silly oscillator concept.
Did I just repeat something trivial that has been discussed to death here before?
Leo

From: Bob kb8tq kb8tq@n1k.org
Subject: Re: [time-nuts] Holdover, RTC for Pi as NTP GPS source
There’s no particular reason to stop at the 100:1 point. You can run multiple
loops at the same time and get out to essentially any level of precision. The
only question is over what averaging interval the precision applies.

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Hi I believe you indeed have tied this back to a number of papers …. Bob > On Nov 2, 2017, at 5:45 PM, Leo Bodnar <leo@leobodnar.com> wrote: > > This is, essentially, how modern delta-sigma DACs work while achieving 24-bit and higher precision using only a single bit converter internally and a lot of clever digital filtering. > Multiple loops are what would be called "higher order" in delta-sigma parlance. > Delta-sigma tech is not poor man's DAC - it has properties that other conversion methods can't achieve, e.g. noise shaping and trivial aliases rejection. > I suspect delta-sigma body of knowledge can be applied almost wholesale to this seemingly silly oscillator concept. > Did I just repeat something trivial that has been discussed to death here before? > Leo > >> From: Bob kb8tq <kb8tq@n1k.org> >> Subject: Re: [time-nuts] Holdover, RTC for Pi as NTP GPS source >> There’s no particular reason to stop at the 100:1 point. You can run multiple >> loops at the same time and get out to essentially any level of precision. The >> only question is over what averaging interval the precision applies. > > _______________________________________________ > 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.

AK

Attila Kinali

Sun, Nov 12, 2017 3:35 PM

Hoi Leo,

On Thu, 2 Nov 2017 21:45:56 +0000
Leo Bodnar leo@leobodnar.com wrote:

I suspect delta-sigma body of knowledge can be applied almost wholesale to this seemingly silly oscillator concept.
Did I just repeat something trivial that has been discussed to death here before?

Trivial? Yes. Well known? No. I know too many engineers who treat
delta-sigma modulators as kind of black magic and don't even want
to touch them. Yes, the math behind it is a bit intricate. There are
things that we cannot even calculate (only simulate), but a second
order D-S modulator will get you quite far and is easy to do.

If anyone wants reading material on that topic, let me know.

		Attila Kinali

--
You know, the very powerful and the very stupid have one thing in common.
They don't alters their views to fit the facts, they alter the facts to
fit the views, which can be uncomfortable if you happen to be one of the
facts that needs altering. -- The Doctor

Hoi Leo, On Thu, 2 Nov 2017 21:45:56 +0000 Leo Bodnar <leo@leobodnar.com> wrote: > I suspect delta-sigma body of knowledge can be applied almost wholesale to this seemingly silly oscillator concept. > Did I just repeat something trivial that has been discussed to death here before? Trivial? Yes. Well known? No. I know too many engineers who treat delta-sigma modulators as kind of black magic and don't even want to touch them. Yes, the math behind it is a bit intricate. There are things that we cannot even calculate (only simulate), but a second order D-S modulator will get you quite far and is easy to do. If anyone wants reading material on that topic, let me know. Attila Kinali -- You know, the very powerful and the very stupid have one thing in common. They don't alters their views to fit the facts, they alter the facts to fit the views, which can be uncomfortable if you happen to be one of the facts that needs altering. -- The Doctor

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Re: [time-nuts] Holdover, RTC for Pi as NTP GPS source