Re: Self adjusting comparator tricks, anybody know any?


Tim Williams wrote:
<john@xxxxxxxxxxxxxxxxxxxxx> wrote in message
news:1144370359.325397.27250@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
The device which Intersil described in
their application note will measure phase very acurately.

Sometimes :)

Many years ago whilst still bright eyed and bushy tailed, I was
suckered into building what was described as a 'precision phase meter'.
Found to my cost it was only 'precision' when measuring waveforms with
0.000% even harmonic distortion and these were (are) as rare as hen's
teeth.

...Run it through a schmidt trigger and frequency divider? Not accurate
enough?

Tim

Be OK. Fine with clean wave shapes (ie balanced/symmetrical). Problems
come with the unbalanced lopsided stuff. Where does each cycle actually
start?. Some kind of additional circuitry is then needed on both phase
channels to (try) and actively servo the signals to a balanced
midpoint, before the phase timing edges can be generated.
john
john

.