Smart defence won’t give you the jitters

Defence applications such as smart munitions depend on ultra-low jitter frequency control. With its latest clock oscillators, IQD presents a solution – one that also boasts robust environmental performance.

Where ultra-low jitter is a prerequisite, IQD provides a solution; the company’s new STXO series of surface mount clock oscillators boasts an ultra-low integrated RMS phase jitter of 256fs at 2.5V and RMS period jitter of 1.4ps over 10,000 cycles. With a phase noise level of -138dBc/Hz at 1kHz and -163dBc/Hz at the noise floor, this ensures the new series is ideal for defence and aerospace applications such as smart munitions, guidance and navigation and communication systems.

With the STXO designed around a hermetically sealed high-shock crystal and a CMOS compatible integrated circuit, the oscillator also promises good environmental performance. The STXO is able, for example, to survive shock levels of up to 20,000G and vibration levels of 20G at 10 to 2,000Hz swept sine, in accordance with MIL-STD-202G.

Temperature compensation
Housed in an industry standard 3.2 by 2.5mm four-pad ceramic package with a metal lid, the new STXO series uses minor temperature compensation to achieve tight frequency stability. It is said to achieve stability of ±10ppm over a -40 to 85°C operating temperature and ±20ppm over the full military operating temperature range of -55 to 125°C.

Frequencies between 10 and 55MHz can be specified, along with a choice of 2.5 and 3.3V supply voltages. Current consumption is 3mA with a 15pF CMOS drive capability. Variants are also available that incorporate enable/disable and tri-state control. Further technical details include a duty cycle of 45 per cent minimum and 55 per cent maximum, with a maximum start-up time of 5ms and a rise and fall time of 5ns maximum.

Tin-lead terminations
In keeping with its military capability, the STXO range can be specified with various termination finishes, including tin-lead. This is particularly beneficial in applications where using a RoHS compliant device would cause approval issues. RoHS compliant finishes are also available for less sensitive applications, however, and the devices are also suitable for use in a variety of demanding industrial applications.