# Best oscilator scheme for watch crystal

I wonder, what's the best oscillator scheme to use with watch crystals(32kHz) to get optimal stability & precision? (provided that temperature is stable, digital correction is out of this topic).

Typical solution is pierce oscillator, but what's the optimal swing/voltage? I have a feeling that sine-wave generator should put less stress on the crystal.

So, what's the best & less stressful oscillator scheme for watch crystals?

That is for digital clock, so long-term stability is important (crystal will be temperature-stabilized & corrected for aging).

• this seems like a heavy opinion question. What is better? What is optimal stability & precision? What defines best and least stressful? – Kortuk Jul 17 '11 at 1:59
• @Kortuk Well, this seems straightforward to me: The more stability the better. I guess driving crystal at excessive swing or improper load or improper waveform might cause it to age faster. – BarsMonster Jul 18 '11 at 1:22
• so cost plays no part? the best stability and life and we are golden? – Kortuk Jul 18 '11 at 7:38
• Yes, as long as we are not going over 1000$in parts :-D – BarsMonster Jul 18 '11 at 7:56 • With that kind of budget ($1000), you can do some fancy things. Temperature control is well within range. Can you get a used HP cesmium clock for that money? – Olin Lathrop Jul 18 '11 at 12:37