Description
Typical Applications
20 X72 Desiger’s Reference and User’s Guide 097-10603-01 Rev. A – November 2004
For simple applications the X72 provides a 5V CMOS-compatible Built-in Self Test
(BIST) Service and a LOCK alarm signal derived from the basic physics operation.
This lock signal indicates when the output frequency is locked to the atomic
resonance of rubidium. When more control over the device is desired, an extensive
command control status dialog is available.
In addition to controlling the operation of the oscillator, the microprocessor's built-in
firmware allows an external host computer to communicate with the embedded
controller through a serial port connection. This allows precise frequency control,
the dynamic frequency selection, the ability to enable and disable outputs, to query
the system's health, and acquire information about the unit's serial number,
operating temperature, fault history, initiate a self test, and other performance
indicators. The protocol used is Symmetricom's proprietary Symmetricom Serial
Interface Protocol, or SSIP.
The simplified block diagram below shows the importance of the digital control in the
unit, how it controls and monitors all aspects of operation, such as the heater
circuits of the physics package, as well as the selection of outputs.
Figure 1-3 X72 Rubidium oscillator simplified block diagram