Crystal oscillators are loosely divided with the frequency they operate at and whether they are fundamental oscillators—work within the frequency marked within the can or at even multiples of that (overtone oscillators). As you can see within the graph underneath, crystals have two resonant details. A reduce impedance sequence resonance https://bookmarklayer.com/story18975010/the-smart-trick-of-bulk-crystal-oscillator-that-no-one-is-discussing