[time-nuts] GPSDO control loops and correcting quantizationerror
Tom Van Baak
tvb at LeapSecond.com
Sat Sep 15 02:10:02 UTC 2012
> I would expect a problem area would be filtering the PWM output. Anything
> you don't filter out will turn into close in spikes. It might be fun to try
> to measure them.
>
> 64K/72 MHz is about 1 ms. 32bits at 72 MHz is 60 seconds.
>
> Has anybody compared DDS style DACs with PWM? The idea is to spread the
> pulses out to make the filtering easier. Instead of 1111100000, you would
> get to work with 1010101010
Hal,
The Z3801A 16-bit DAC is dithered at 102.4 Hz and LP filtered. Details and plots:
http://leapsecond.com/pages/z3801a-efc/
/tvb
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