Teledyne LeCroy LabMaster 10Zi Operators Manual - Manual (Page 80)

LabMaster 10 Zi Oscilloscopes
72
922561-00 Rev A
LabMaster Deskew Calibration
The ChannelSync™ architecture in LabMaster modular oscilloscope systems
utilizes a single 10 GHz distributed clock for all acquisition modules. This
provides precise timing alignment and timing accuracy between all channels
in all acquisition modules as found in a single, conventional oscilloscope
package. However, to ensure that the static skew of all connecting cables is
accounted for, a calibration is required for the most accurate results.
Deskew calibration eliminates:

Static skew due to minor differences in length of PCIe
interconnection cables. LabMaster modular oscilloscopes may consist
of multiple acquisition modules. These multiple modules need to
deskewed with respect to each other to account for connection cable
propagation delay (static skew). This propagation delay is normally
100-200 ps and is a result of the very small differences in length
between the PCIe cables used for connections on your particular
LabMaster setup.

Minor static skew differences between channels and gain settings in
a single acquisition module.

The small amount of static skew remaining after the factory
hardware deskew. At the factory, channels in each Acquisition
Module are deskewed in hardware to within approximately 2 ps at 20
GHz. This can vary slightly over varying gain ranges (V/div settings) on
each channel. Depending on the timing accuracy desired for your
measurements and the bandwidth of your acquisition module, you
may need to correct for this.

Static skew introduced by probe and cable connections. With probes
and cables connected to the acquisition module, additional static
skew will be introduced. When these devices are attached, deskew
signals must be respectively deskewed to each other is again
required to eliminate the propagation delay of the signal due to
these items being added to the signal path.