[time-nuts] DMTD - analog multiplier vs. diode mixer ?
magnus at rubidium.dyndns.org
Tue Jan 5 18:58:01 EST 2016
On 01/06/2016 12:28 AM, Poul-Henning Kamp wrote:
> In message <568C46B9.4020303 at rubidium.dyndns.org>, Magnus Danielson writes:
>> The white noise will be particularly annoying as it then converts to
>> jitter through the slew-rate limitation as you go into the
> Digitize the LPF output and do a curve-fit to find the zero-crossings ?
That would work. You could least-square fit it with very cheap
processing. The LPF would mainly need to reject the sum frequencies to
act as anti-aliasing filter, and the noise would be filtered out by the
Estimating the phase and slew-rate, and then use those to calculate the
actual through-zero phase would not be too hard. As a consequence you
get a slew-rate monitor, which act as an observation of signal level.
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