How to use OCXO oscillator ?

[goldperson2005]

Hi
I haven't used OCXO 'Oven Controlled Crystal Oscillator' up to now .
Datasheet

Where the 'Reference Voltage' and the 'Control Voltage' should be connected to ?

 

[barry]

A data sheet might help, or, at the very least, a part number. Posting a pinout table is meaningless.

 

[keith1200rs]

There is a datasheet in the first post - but it is not obvious.

Best to read the application note: https://www.abracon.com/Precisiontiming/AOCJY_Vref_App_Note.pdf

Keith.

 

[barry]

Ok, missed that data sheet. Compliments on how well hidden it was.

The Reference Voltage is an output (read the datasheet). It's not clear, but it must be from some internal reference.

The Control Voltage is used to adjust the output frequency +/- 0.7 ppm (READ THE DATASHEET)

 

[goldperson2005]

Thanks a lot dear Keith
Just one ;
I can not understand that , is the 'Control Voltage' pin for fixing the output frequency in different temperatures or defining the output frequency ?

 

[RCinFLA]

Control voltage is for fine tuning (warp). If you need exact 10 MHz to high accuracy you need a good secondary reference to compare and set the control voltage to yield exactly 10 MHz.

Keep in mind you can screw the inherent frequency stability of unit by poor Control voltage control. For example, in the application note it uses a resistor voltage divider from internal reference voltage to set control. Noise from your circuit on control line can degrade close in noise of OCXO. If resistors have temp coefficient that changes the yielded resistor divided control voltage then the frequency will drift per the temp coeff. of the resistor divider degrading the inherent stability of the OCXO.

One application is taking output and dividing down to 1 pps and comparing over minutes of averaging to a 1 ppm from a GPS receiver. A very long time constant algorithm with very small adjustments is made on the control voltage to keep the OCXO locked to the 1 ppm long term average from GPS receiver. This is called 'disiplining' the OCXO and can provide a couple ppb of frequency stability.

 

[goldperson2005]

Thanks .
I want put it very close to a chip that is so sensitive around temperature , then its so important for me to know :
Does OCXO have influence on other parts of circuit that are close to it ?