measure oscillator with 2 outputs

[bosskardo]

How do I measure something like that with oscilloscope? Can I put signal to one and GND to other output? Or do i need to use 2 probes and get the difference?

 

[KlausST]

Hi,

it´s a differentialoutput, thus the signals are usually specified as "difference". A single ended measurement is useless unless specified otherwise or you use a Balun.

Shorting one signal to GND may also be against load specification. Maybe causes failure or damage.

--> read the datasheet, it should provide all necessary details.

Klaus

 

[danadakk]

The two outputs are complements of each other, so more "standard"
measurment would be two channels on scope, 2 probes, both probe grounds
connected to osc ground, and the probes one on Out and the other on
Out2

That way you can look at skew between outputs if that is of concern.

Regards, Dana.

 

[FvM]

Single ended measurements off a differential LVDS are not completely useless, they are sufficient to check e.g. for presence of a signal, frequency etc.

A 180 MHz clock can't be checked for signal quality with a standard passive probe. The best way to measure the signal in circuit is a differential active probe.

 

[danadakk]

When doing measurements make sure you do the DSO calibration before
actual measurement, including probe calibration. Hopefully you scope has
ac timing cal on probes

Regards, Dana.