There has always been confusion between resonators and crystal oscillator. In order to help practitioners to distinguish these two kinds of component, Easybom did a investigation and here’s what it came out.
What is a resonator?
Resonator refers to the electronic components that produce resonant frequency, which are commonly divided into crystal resonator and ceramic resonator by composing materials. The function of generating frequency has the characteristics of stability and good anti-interference performance, so it is widely used in all kinds of electronic products.
The frequency accuracy of crystal resonator is higher than that of ceramic resonator, but the cost is also higher than that of ceramic resonator. Resonators mainly are used for frequency controlling. All electronic products related to frequency transmission and reception need resonators.
What is a crystal oscillator?
An oscillator is an electronic component used to generate repetitive electronic signals (usually sinusoidal or square waves). The circuit it forms is called an oscillating circuit, which can convert direct current into an electronic circuit or device with AC signal output at a certain frequency.
Oscillators can be roughly divided into two categories: harmonic oscillator (also known as linear oscillator) and relaxation oscillator (which is nonlinear). They are commonly used for oscillating culture of various liquid and solid compounds such as biology, biochemistry, cells, bacteria and so on.
Resonator VS Crystal Oscillator: Merits and drawbacks
After further researches, Easybom discovered that, besides applications, resonators and oscillators are different in aspects of frequency range, output, tolerance, sensitivity, structure, compositions of circuit and manufacturing difficulties.
- Crystal oscillators convert a frequency range of about 10000Hz-100MHz whereas resonators’ frequency range varies from approximately 190 KHz – 50MHz.
- Crystal oscillators offer a more accurate output than resonators do.
- Also, crystal oscillators beat resonator in the stability of the output frequency for the reason that crystal oscillators have less dependency on temperature changes and vibration modes.
- As for ESD tolerance, crystal oscillator has lower tolerance than the resonator does. In terms of sensitivity, oscillators are more sensitive.
- The resonator is a resonant element, and the oscillator is a complete set of circuit units, which can include some frequency selection elements, but not all of them.
- Resonator is a passive device, which needs peripheral circuit to drive its work and produce clock output. The oscillator is an active device and has a built-in circuit to provide a more stable clock output.
- Resonator is much easier to manufacture while crystal oscillator is more difficult to make due to materials used.
Shall we replace resonators with crystal oscillators?
From the comparisons above, it’s clear that crystal oscillators surpass resonator in almost all aspects. However, Easybom think that it’s not yet to come to the conclusion that we should replace the latter with the former since they have different applications after all.
To better meet our requirements in applying resonators, we could follow these methods: pay attention to temperature characteristics of circuit components, check whether the actual oscillation frequency is within the desired frequency range, and keep oscillation amplitude at appropriate level.