Technical data

176 Notes on USB Electrical Compliance Testing
6 Troubleshooting Hi-Speed Test Failures
• Mask Template — If you choose to use the SDA software option to
perform data eye tests, you need to select the appropriate mask
template to use for the eye diagram.
• MATLAB scripts version — Allows you to select between MATLAB
scripts version 2.10 or 2.12.
• Threshold — Allows you to select or enter the voltage level to use when
measuring SYNC field or EOP widths. Noisy signals may have ripples at
the end of the EOP; therefore, a higher level should be chosen to avoid
the ripples.
• Trigger Level — Allows you to select or enter the voltage level to use
when triggering on the inter- packet gaps. Noisy signals may have low
amplitudes; therefore, the trigger level should be reduced.
• Inrush Current Time Range — Allows you to select the total time range
to capture inrush current.
• Inrush Current Trigger Level — Allows you to select the trigger level to
use to capture inrush current. Self- powered devices may draw very
little current, so the trigger level should be reduced.
Also useful for debugging problems is the EZJIT analysis software option
for the oscilloscope.