Resonators, Oscillators, and Crystals, OH MY!

I’m having a little problem with terminology. I know that when someone talks about a “resonator” in the electronics sense, the generally mean a ceramic resonator. I also know that these ceramic resonators come by themselves, or in nice little 3 pin packages with included load capacitors.

I need something more frequency-stable than a (ceramic) resonator, so I figure I will need something based on a quartz crystal. I head over to digikey, and find two large categories: “Crystals” and “Oscillators”

What exactly is the difference between these two terms, in the electronics sense? They all look similar to me, and individual data sheets aren’t of much help.

Also, is it common to find a crystal (or oscillator) with internal load capacitors, or will I need to supply these myself?




My understanding is that the oscillator has built-in circuitry so you just need to add power and you get a square wave out. With the crystal alone, you need to add an external circuit. Usually, small microcontrollers have the circuit built-in, so you just need to add the appropriate capacitors.

- Jan

Thanks, I just ordered a few different kinds of crystals (and the associated capacitors) from Digikey like five minutes ago, and it was still bugging me. I feel much better now.


I think crystals are themselves a specific kind of oscillators. Correct me if I am wrong! I think There are many ways go get a square wave output but crystals are the easiest and cheapest…