How to Specify
Quartz Crystals
Quartz crystals are the most technically simple product we offer, the package contains only a piece of quartz wafer, all the supporting circuitry needed to create the oscillation must be provided by the customer’s circuit. The quartz wafer inside is cut and shaped to give a resonant frequency within the specified limits. Our quartz crystal part numbers all contain the code XTAL ......
Clock Oscillators
Clock oscillators are the most technically simple oscillator we offer, the package contains a quartz wafer and also the necessary circuit to make the quartz resonate. Consequently by applying the correct power supply to the device a stable output clock waveform is provided at the output pin. Our clock oscillator part numbers all contain the code SPXO. SPXO is an acronym for Simple Packaged Xtal Oscillator ......
VCXOs (Voltage Controlled Crystal Oscillators)
Voltage Controlled Crystal Oscillators give a stable clock output waveform which can be changed via an analogue voltage input. The technology makes use of the pullability of the crystal, its change in frequency due to change in load capacitance. The voltage input is used to vary the load capacitance of the crystal circuit within the oscillator, this gives a very controllable change in output frequency which can be used to tune the device to match the exact frequency required while the circuit is active. We use the code VCXO to denote our voltage controlled quartz crystal oscillator part numbers ......
TCXOs (Temperature Compensated Crystal Oscillators)
Temperature Compensated Crystal Oscillators give much tighter frequency stabilities than standard clock oscillators. The frequency over temperature change of the quartz crystal is internally monitored and compensated for using a similar process to that used inside a VCXO. As a result the frequency change seen on the output is significantly reduced. Some temperature compensated voltage controlled crystal oscillators also give a further fine tuning function to allow the customer to make changes to the output frequency while the circuit is active ......
OCXOs (Oven Controlled Crystal Oscillators)
Oven Controlled Crystal Oscillators offer frequency stabilities even tighter than those offered by a TCXO. The frequency drift of the quartz crystal due to temperature shift is reduced by heating the crystal in an oven and so holding the temperature of the quartz at a fixed point. Traditionally this technology meant physically large devices with heavy power consumptions, however technology is constantly developing and we are proud to offer some of the smallest OCXOs in the world. We use the code OCXO to denote our oven controlled quartz crystal oscillator part numbers ......
GPS Disciplined OCXOs
Are you using GPS as a timing reference? Are you using some other timing source as a reference? Does this result in a 1 pulse per second (1PPS) signal? What happens when you lose GPS, or your reference source?Clock modules, also known as GPS disciplined oscillators GPSDO’s, are here to maintain timing accuracy (or 1PPS phase synchronisation) in the event that you lose GPS, or your reference source. This is called holdover mode.....
Rubidium Oscillators
IQD currently offer two very small sized Rubidium products. The smallest being the IQRB-1, and the newer IQRB-2 which has improved phase noise performance. Due to the complex nature of the devices any variations to the specification require engineering input, therefore please contact our Application Support team to discuss developing a customised version of the product to suit your specific needs.......