Release date:2020-07-06
First, the consideration of frequency stability
One of the main characteristics of crystal oscillator is its stability in the operating temperature range, which is also an important factor in determining the oscillator price.
Second, the output
Each output type has its own unique waveform characteristics and USES. Attention should be paid to the requirements for three states or supplementary outputs. Symmetry, rise and fall times, and logic levels are also specified for some applications.
Phase noise and jitter
The phase noise measured in the frequency domain is a real measure of short-term stability. It can be measured within 1Hz of the central frequency, usually up to 1MHz. The phase noise of the oscillator is improved at frequencies far from the center. Jitter is related to phase noise, but it is measured in the time domain. Jitter that can be expressed in microseconds can be measured as RMS or peak-to-peak values.
Influence of power supply and load
The frequency stability of the oscillator is also affected by the variation of the oscillator's supply voltage and the variation of the oscillator's load. The correct choice of oscillator minimizes these effects. The designer should test the oscillator performance against the recommended voltage tolerance and load.
Crystal vibratory packing
Like other electronic components, clock oscillators are getting smaller and smaller. Small packages often have tradeoffs between performance, output selection, and frequency selection.
6. Work environment
The practical application of oscillators requires careful consideration. For example, high vibration or shock levels may cause problems with the oscillator.
