The Frequency stability of OCXO is twice as much as TCXO, so OCXO is more stable. Xtaltq Technologies' TCXOs improve stability ±0.05ppm to meet customers' design and reduce dfiiference.TCXOs are smaller and more economical than OCXOs. They are a terrific solution for portable units that necessitate a reasonably accurate source. On the other hand, OCXOs might be more expensive and come with a larger footprint, but the precision of their frequency signal can’t be beat.
Temperature Compensated Crystal Oscillator TCXOs require a short warm-up period (normally 100ms, or sometimes longer depending on the unit’s design). The warm-up allows all of the components to reach thermal equilibrium and ensures that the device delivers a precise signal. Usually, TCXOs are coordinated with PLL circuits in application to provide clock frequency needed by systerm. If different subsystems require clock signals of different frequencies, they can be provided by different phase-locked loops which are connected by the same crystal.
A longer warm-up period is required when using an Oven Controlled Crystal Oscillator OCXO because the oven will only begin to operate once it hits a precise temperature (some OCXO heaters actually require about an Amp of power during this time). Additionally, the on-going heat supply that the “oven” is maintained at requires a considerable amount of power, too. Such a high level of power consumption means that an OCXO cannot be run solely on batteries.OCXOs are widely used to high-end measuring equipments such as freqeuncy meter, signal generator etc.
Whatever they are used to provide for signal source and guarantee baselien time for equipments, they can replace each other.