The X72 is a 5th generation rubidium oscillator. It runs in a temperature range of -40C to 85C. It only uses a single supply voltage. It can be controlled with a 0.8 in card slot. It operates between 10v and 32 vdc. The physics package (bulb and resonator cell) have a 20-year warranty. It is microprocessor based and allows for serial command selection and enabling of TTL-level digital outputs. It also contains a sine output. It has a 1 PPS signal output through the RS232 protocol. It has a 5V BIST, and an extensive command dialog window for the internal firmware, both accessed through a proprietary serial port. When the output signal has locked onto the rubidium frequency, a lock signal is driven low. This allows for dynamic frequency selection, disabling and enabling of outputs, system health updates. The system has no reverse polarity protection circuits.
It must be attached to a base plate and it is recommended to add a heat sink to the unit. If the temperature increases above 85C then the physics package shuts down and the temperature coefficients rise to $6e-10$. As long as the base plate thermal ramp rates are less than 2C per minute, condensation will not be a problem. The chassis of the frequency standards is tied to signal grounds. The power supply return is isolated from the chassis and signal grounds by a ferrite bead. This is a robust grounding solution that may cause ground loops if not carefully considered. To break DC ground loops you must use an isolation transformer for the sine output, and a float transformer for the secondary winding of the power supply. All outputs are short-circuit protected.
[[Breaking Ground Loops]]
[[X72 Dimensions]]
X72 Pinout
[[X72 Absolute Ratings]]
Sources
- X72
Backlinks
Built-in Self Test
[[CDMA]]
[[Cellular Base Stations]]
[[GPS Receiver Clock Errors]]
[[Microprocessor]]
[[RS-232]]
[[Rubidium Oscillator]]
[[Sine Wave]]
[[UART Uses]]