LVDS Spec - not enough information?

Thread Starter

matthej

Joined Oct 10, 2020
66
Hi,

I am looking at a specification for an LVDS clock oscillator. The specification is below. As you can see there is no mention of common mode voltage or voltage swing, only Voh and Vol levels. Don't I need more information that what is in the datasheet?

If I take the Voh at 1.6V and Vol at .9V, my voltage swing would be 700mV, but what is the smallest voltage swing? My receiver is expecting a 100-600mV


Screenshot 2021-11-18 094452.png
 

KeithWalker

Joined Jul 10, 2017
3,063
The spec sheet gives you the absolute limits of the spread of the output logic levels. What more do you need? If you want larger signals, use a digital buffer/amplifier on the output or a different clock chip.
 

Thread Starter

matthej

Joined Oct 10, 2020
66
The spec sheet gives you the absolute limits of the spread of the output logic levels. What more do you need? If you want larger signals, use a digital buffer/amplifier on the output or a different clock chip.
No mention of common mode voltage.
Do I assume the spread then can be 700mV?
 

KeithWalker

Joined Jul 10, 2017
3,063
The single output is logic level digital pulses. Why do you need common mode voltages? Use a logic level shifter to match it to your receiver.
 

KeithWalker

Joined Jul 10, 2017
3,063
On second thoughts, maybe you have picked the wrong type of crystal oscillator. They are available with either digital or analog signal output. What is the full requirement of your receiver clock input?
 

Thread Starter

matthej

Joined Oct 10, 2020
66
The single output is logic level digital pulses. Why do you need common mode voltages? Use a logic level shifter to match it to your receiver.
This is a differential signal. The receiver is expecting a certain common mode voltage for it to work properly. Not sure what to level shift to if I don't know where the signal is at
 

KeithWalker

Joined Jul 10, 2017
3,063
This is a differential signal. The receiver is expecting a certain common mode voltage for it to work properly. Not sure what to level shift to if I don't know where the signal is at
Does the receiver require digital pulses or an analog sine-wave input?
 
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