PXIe Platform Bit Error Rate Tester
|
BERTPXIe-1003/1005
Coherent Solutions Ltd.
Version
1.00
42
8.5.1.2
Example of setting the pre-cursor and post-cursor de-emphasis
Consider the following pre-cursor and post-cursor example:
The “Peak Swing” is set by the
AMPLITUDE field. The de-
emphasis control leaves the “peak
swing” unchanged but it reduces the “De
-
emphasized Swing” to provide the desired
level of de-
emphasis. If we use
d
to represent the de-emphasis,
m
to represent the peak swing, and
n
to
represent the de-emphasized swing,
d
is calculated as follows:
𝑑 = 20 × log (
𝑚
𝑛
)
If the value of the AMPLITUDE field (peak swing) is set to 800 mV, and the value of de-
emphasized swing is 505 mV, it can be calculated that the value of the DE-EMPHASIS field
must be set to 4 dB.
8.5.1.3
Set the amplitude
For each PPG channel, you can set the amplitude of the output voltage. The set value must be
within the valid range, which is from 200 mV to 1100 mV.
To set the amplitude for a channel, type an appropriate value in the AMPLITUDE box.
