Tektronix TDSDDM1, User Manual

Page: 63 / 102

Measurement Descriptions
TDSDDM1 Disk Drive Measurement Application User Manual
3–21
50% Pulse Width (Positive), PW50+
50% Pulse Width (Negative), PW50–
The PW50+ measurement is the average pulse width around a track. It is the
width of the pulse at 50% of TAA+. Only positive pulses are measured.
The PW50– measurement is the average pulse width around a track. It is the
width of the pulse at 50% of TAA–. Only negative pulses are measured.
Figure 3–14: PW50+ measurement
PW50+ is defined as the pulse width at 50% of the peak value of the pulse. Only
peaks are measured. The baseline reference for measuring the peak is zero volts.
PW50– is defined as the pulse width at 50% of the trough value of the pulse.
Only troughs are measured. The baseline reference for measuring the trough is
zero volts.
The application performs the measurement according to the same algorithm used
in the PW50 measurement, described on page 3–18, with the exception that only
positive pulses are measured for PW50+ and only negative pulses are measured
for PW50–.
Definition
Test Methodology