Crystal oscillators are loosely divided via the frequency they perform at and whether they are elementary oscillators—function within the frequency marked about the can or at even multiples of that (overtone oscillators). As you could see from your graph underneath, crystals have two resonant points. A reduced impedance sequence resonance https://ariabookmarks.com/story4657193/the-smart-trick-of-bulk-crystal-oscillator-that-no-one-is-discussing