Teledyne LeCroy QPHY-SAS2 - Manual (Page 27)

QPHY-SAS2 Software Option
917718 Rev A
27
QPHY-SAS2 TEST DESCRIPTIONS
Tx Group 1 Out of Band Tests 5.1.x (OOB)
There are 4 tests run in this group. The tests that are run are:
1. 5.1.2 – Tx Maximum Noise During OOB Idle
2. 5.1.3 – Tx OOB Burst Amplitude
3. 5.1.4 – Tx OOB Offset Delta
4. 5.1.5 – Tx OOB Common Mode Delta
After the completion of the Out of Band Tests the oscilloscope is in the following configuration:
Figure 17 - Oscilloscope Configuration after Out of Band Tests
Shown on this screen:

F3 is the Idle Differential Signal. This trace represents only the idle portion of the differential OOB signal.

F4 is the Burst Differential Signal. This trace represents only the burst portion of the differential OOB signal
after it is filtered by a 4.5GHz low-pass Butterworth filter.
Having these 2 traces separate from each other allows us to perform the measurement on the idle portion and the
burst portion separately.

F5 is the Burst Common Mode signal.

F6 is the Wide Band AM Demodulated Differential Signal. This is used for the separation of the idle portion
from the burst portion.

F7 is the Idle Common Mode signal. This is calculated by summing the two inputs and dividing them by 2.

F8 is a view of the Differential Signal after it has been filtered by the 4.5GHz low-pass Butterworth filter. This
is calculated by subtracting the negative input from the positive input. This signal is used to create many
of the traces described earlier.