Chip Scale Atomic Clock GPSDO (CSAC)

The CSAC GPSDO is the first commercial Chip Scale Atomic Clock (CSAC) available on the market. VIAVI Solutions has teamed with Microsemi to integrate its SA.45s CSAC into the CSAC GPSDO module. The CSAC GPSDO is a game-changing, disruptive technology culminating from decades of research sponsored by the U.S. Government. It is a breakthrough technology that allows a Cesium Vapor Cell Atomic Reference Oscillator to be packaged in a unit several orders of magnitudes smaller than legacy products, with more than an order of magnitude in power reduction, while out-performing many industry-standard Atomic Oscillators.

The CSAC GPSDO also includes a high-performance time-interval counter that measures the internally generated 1 PPS signal from an internal 50-channel GPS receiver or an externally supplied 1PPS reference signal with a resolution of 20 picoseconds. The CSAC oscillator is phase-locked to either of these two 1 PPS signals with better than 0.3 ns average phase accuracy typically, and typically provides better than 5E-12 stability per day in holdover.

Highlights

• Full atomic lock achieved in 110 seconds max. (<60 s typical) after power on
• Phase noise of <125 dBc at >100 Hz offsets using an integrated phase noise filter
• Power consumption of <1.4 W (Sine outputs) and <1 W (CMOS option)
• Less than 0.1 ppb per g per axis typical g-sensitivity
• Better than 1 µs drift per day typical in holdover
• A high-end WAAS/EGNOS/MSAS GPS receiver drives a Chip Scale Atomic Clock frequency reference under the control of a 32-bit Processor
• Holdover mode with aging compensation
• Controlled via RS-232 and USB control using standard SCPI commands. Settings are automatically stored in non-volatile memory
• 10 MHz, 5 MHz, and 1 PPS outputs
• GPSCon Windows graphing and SNTP server software compatible