Teledyne LeCroy QPHY-SAS3 - Manual (Page 28)

• HighMode (P5) is the maximum peak from the right side of the F5. This represents the de-
emphasized high voltage level of the signal. These are used to calculate the VMA.
• VMA (P6) is the difference between the 2 modes of the histogram. This is the measured value of Tx
- VMA (5.3.5a). This value must be less than 600mV in order to pass this test.
• EQ (P8) is calculated as 20*log
10
(V
p-p
/VMA). This is the measured value of Tx - EQ (5.3.5b). This
value must be between 2 and 4 dB in order to pass this test.
Tx 5.3.6 Rise and Fall Times (HFTP)
The purpose of this test is to verify that the rise and fall times are within the specification limits. After the
completion of this test the oscilloscope is in the following configuration:
Figure 21 - Oscilloscope Configuration after the Rise and Fall Times Test
Shown on this screen:
• F1 is the differential input waveform.
• F4 is the histogram of all of the measured 20-80 rise times.
• Z2 is a zoom of F1.
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