The SPXO is a space3-qualified high frequency quartz-crystal-controlled clock for satellite data-bus systems. It is a simple-packaged crystal oscillator using an overtone AT-cut resonator, fabricated from Airbus Defence and Space-grown High Purity Quartz. This material is the purest and most highly qualified quartz in the world and provides the SPXO resonator with excellent intrinsic radiation tolerance. The design utilises Advanced CMOS AC logic devices for low power and high speed. The circuit is implemented using surface-mount technology, with hermetically encapsulated integrated circuits, in a vented aluminium box.
|Frequency||20 to 100MHz|
|Stability (all causes)||<±100ppm (10 years)|
|Stability (with temperature)||±50ppm|
|Stability (with setting)||±20ppm|
|Stability (with voltage)||±10ppm|
|Duty cycle||50:50 nom|
|Rise/fall time||<5 nSec|
|Power consumption||300 mW nom.|
|Supply||5 ±0.5 volts|
|Size||32 x 22 x 10 mm|
The SPXO oscillator can be used as the microprocessor clock to provide the synchronisation signal in spaceborne applications where quartz crystal controlled timing stability is required together with low mass, size and power consumption.