Digi-Key has Panasonic ceramic resonators down to 400kHz not SMD though. As far as the when to use Ceramic vs. Crystal thread the answer depends on the price/performance requirements of your particular design. - -Mark jurram@torrington.com >>> Sean RS Costall 18 July 1996 2:39 am >>> Assuming that ceramic resonators are, in fact, cheaper than crystals, are they available in very low frequencies? All I have been able to locate is 4 MHz and up parts. I would need one that worked at 32 kHz. (Running at 4MHz and sleeping 99.9% of the time is not an option.) If anyone knows of any, please reply to me at costalls@cuug.ab.ca or post to the list. SMD parts are preferred, BTW.