Chip scale atomic clock features low phase noise

May 21, 2014 // By Graham Prophet
Microsemi claims it has the only commercially available low noise chip scale atomic clock (LN CSAC), a portable atomic clock with leading-edge performance and specifications such as low noise, which is a critical parameter in many radar and communication applications for both military and industrial sectors.

Microsemi's LN CSAC combines the best of oven-controlled crystal oscillator (OCXO) and standard CSAC technologies by employing an ultra-low power crystal oscillator within the control loop of the atomic clock to optimise Allan deviation and phase noise. It improves on the performance of the company's prior CSAC.

The LN CSAC joins Microsemi's Quantum family of atomic clocks. Its phase noise performance of -87 dBc/Hz at a 1 Hz offset and a noise floor of -155 dBc comes with a power consumption of only 240 mW. The Allan deviation at 1 second improves to less than 2E-11. LN CSAC maintains the timing subsystem capabilities of CSAC, which include one pulse per second (PPS) steering and distribution, digital frequency control, comprehensive telemetry and diagnostics, and time of day (TOD) generation.

"LN CSAC leverages the leading edge ultra-low power atomic clock technology developed by Microsemi to produce the only commercially available low power frequency reference and timing module unique within the industry," said Peter Cash, business area director of Microsemi's Space, Defense and Avionics (SDA) business.

"This new device produces atomic clock accuracy and crystal oscillator signal purity that can operate using battery power to provide low power signal generation for a broad range of applications. These capabilities operate within the volume of typical ovened crystal oscillators using a fraction of the power, with features common in sophisticated timing modules."