One of the key things you need to know before purchasing a crystal oscillator is expected costs. There are multiple ways and specifications that can quickly drive up (and down) the costs of OCXOs and other crystal oscillators. In this post, you'll learn the top 8 cost drivers for crystal oscillators in order of most influential to least influential.
By the end of this post you'll have a much better idea of where to focus your cost-cutting efforts and to save the most in the long-term. Much of it just depends on your specific application and needs and where you're able to be more flexible.
Note: Oscillator pricing is very dependent on your specific needs and application. Be sure to contact us for specific information and pricing based on your needs.
The top 8 crystal oscillator cost drivers (in order) include:
- g-sensitivity
- Phase Noise
- Operating Temperature
- Stability (FvT)
- Allan Deviation (ADEV)
- Voltage
- Frequency
- Package Size
Let's dive deeper into understanding each cost driver.
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The Top 8 Cost Drivers of Crystal Oscillators (In order of potential cost sensitivity)
1. Oscillator G-Sensitivity (g-Compensation)
Not everyone needs g-compensation oscillators in their application. However, if your application is subject to high levels of vibrations, g-forces, or microvibrations (or you work in an industry such as military or space), odds are you will need to consider g-sensitivity oscillators.
G-sensitivity oscillators (or g-compensated or high-vibration oscillators) can get expensive. Whenever the crystal inside an oscillator is exposed to vibration or g-forces, it can quickly and dramatically throw off the oscillator's desired center frequency.
A lot of technical engineering goes in to making an oscillator resistant to g-force and vibration deviations to maintain that desired frequency and phase noise. This is especially important in critical military & defense applications as you can probably imagine.
The very technical and precise nature of g-compensation in oscillators drives up the costs very quickly. It can be very difficult from an oscillator/RF engineer's perspective. Therefore, the more g-compensation that's needed, the higher the costs.
Active and passive compensation are 2 of the main methods used in effective g-sensitivity oscillators. (Along with using high-stability crystals).
2. Oscillator Phase Noise
There are so many potential external factors that can lead to unwanted phase noise in crystal oscillators. These include vibrations, temperature deviations, aging, and more. Similar to g-sensitivity, a lot of fine engineering technicalities go into keeping oscillators free of phase noise. Both with the crystal and oscillator unit. This naturally causes the process to become more costly.
The more resistant an oscillator needs to be to phase noise, the more difficult it is to manufacture to maintain a clear, stable frequency over time. Therefore, the better the phase noise requirements, the higher the costs (typically). Phase noise is typically more sensitive to cost increases compared to other requirements.
3. Operating Temperature Range
An oscillator's operating temperature earns the #3 spot on our cost sensitivity list.
The wider the oscillator's operating temperature range becomes, the more difficult it becomes to design and manufacture to maintain a precise frequency or phase noise level.
Therefore, the wider the required operating temperature range, the higher the costs (again assuming all other specifications remain untouched).
While this may not impact costs as much as g-compensation or oscillator stability, it is still a significant source of potential added costs.
4. Oscillator Stability (Frequency vs. Temperature)
Crystal oscillator stability is very similar to g-compensation in that it can be very technically challenging from an oscillator design perspective to maintain high stability over a long period of time.
External elements such as temperature deviations can cause the oscillator frequency and phase noise to drift. A lot of technicalities go into the crystal cut and oscillator unit itself to help maintain the precise frequency and/or phase noise level over time, therefore driving up costs (potentially quickly). The higher the stability, the higher the costs (assuming everything else is constant).
Therefore, we believe stability is deserving of the #4 spot on our cost sensitivity list.
5. Allan Deviation (ADEV)
Allan Deviation, in simple terms, can be translated to short term stability. ADEV drives up costs just like oscillator stability (FvT). However, long term stability can be much more difficult to maintain compared to ADEV (from a manufacturing perspective). Therefore, higher ADEV requirements will not drive up costs as fast as FvT (long term stability).
6. Oscillator Input Voltage
While the oscillator's input voltage doesn't typically play one of the larger roles in cost, it should still be noted.
As an oscillator's input voltage requirements are lowered, the harder it becomes to hit performance. Therefore, this can drive up the costs.
Basically, the lower the voltage (while trying to achieve best performance) the higher the costs are likely to be.
Of course like most of the other requirements, it will all depend on your specific requirements and application. Be sure to contact us for specific information and pricing.
7. Oscillator Frequency
If all else remains constant, an oscillator's center frequency requirements can be significantly adjusted without much additional costs added. Exceptions include very odd/custom frequencies (that aren't commonly used in many applications) or very high frequencies. Yield will be impacted on the crystals.
8. Package Size
Oscillator package size has the least influence on costs. However, it makes enough of a difference to still mention on our list.
The smaller the package dimensions, the harder it becomes to fit in all the required oscillator circuitry and electronics. This is especially true if there are a lot of other heavy requirements in other areas (g-compensation, phase noise, temperature range, etc).
Typically, the smaller the package, the higher the costs. However, adjusting package size does not impact the price as much as other requirements (as long as it is achievable from a manufacturing perspective given other customer requirements. Contact the oscillator manufacturer for more specifics.)
