User guide

• Low Level
The Low Level is the mean of the lower dBER/dTh distribution. It is calculated
as:
• Mean Level
The Mean Level is the middle between the High and Low Levels, calculated as:
• Amplitude
The Amplitude is the difference between its High and Low Levels.
• Threshold Margin
The Threshold Margin is the distance between the upper and the lower BER
curves at the position given by the BER Threshold setting.
The noise result parameters are summarized in the following table:
Table 28
Parameter Name Pass/Fail
High Level Std. Dev
Low Level Std. Dev
Peak Peak Noise max
Signal/Noise Ratio (RMS) min
Signal/Noise Ratio (Peak Peak) min
For some of these parameters, pass/fail limits can be set, as indicated in the table.
The noise parameters are defined as follows:
• High Level Std. Dev.
The standard deviations are derived from the dBER/dTh histogram.
The High Level Standard Deviation is calculated as:
6 Advanced Analysis
278 Agilent J-BERT N4903B High-Performance Serial BERT
Noise Results