Teledyne LeCroy AORM - Advanced Optical Recording Measurements - Manual (Page 56)

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ISSUED: June 2013 923133 Rev A
More On Edge Shift
A good approach to understanding the operation of the edge shift parameter with different modes
of operation starts by considering the next figure, a histogram of 3T to 5T pit widths.
2.5 3 3.5 4 4.5 5 5.5
0
200
400
600
3T Widths
4T Widths
5T Widths
Histogram of Pit Widths
Pit Width / T
Population
The Edge Shift parameter takes on each of these distributions separately. For each distribution, the
ideal width (nT) is subtracted from the pit widths and the difference is calculated in percent. As a result,
the Edge Shift distributions are calculated, shown in the next figure.
1.16 µs 690
ns
695
ns
voltage
threshold
920 ns
5T 3T 3T 4T