Teledyne LeCroy WaveExpert 100H Operators Manual User Manual
Page 73
Wave Expert
WE-OM-E Rev A
71
∫
=
2
1
)
(
2
1
t
t
dt
t
Z
L
for inductance, and
dt
t
Z
C
t
t
∫
=
2
1
)
(
1
2
1
for capacitance. Note that the reactance values are only approximate and do not
take into account the affect of multiple reflections from impedance mismatches
before the section being measured.
TDR mode allows you to measure time domain reflectometry (TDR) and time domain transmission
(TDT) parameters to characterize the signal integrity of your device under test (DUT). TDR/TDT
mode measurements are made either for Single-ended or Differential measurements, using an
ST-20 (20 GHz TDR module) in any scope channel.
Differential measurements involve a deskew process to adjust the skew between the
simultaneously generated steps from two TDR modules. This enables true differential
measurements of the DUT.
The TDR main menu allows you to select the channels used and to control the Rise Time of the
reflected pulse from the DUT. A calibration wizard guides you through the calibration process, for
either single-ended or differential devices, to make TDR and TDT measurements.
The calibrated trace, also referred to as the Normalized trace, can then be adjusted in the TDR
Normalization dialog where you can select the measurement format, either Impedance or
S-parameter, and adjust the display of the measured parameter.
Cursors can be used to verify the impedance, voltage, and reflection of a selected point on the
waveform trace. TDR/TDT cursors are displayed by turning on cursors from the menu bar. The
Y-axis markers will then track the waveform at the position determined by the X-axis marker. (See
“Measuring with Cursors” in the WaveExpert Operator’s Manual.)
Required Equipment
• ST-20 module for Single-ended TDR measurements
• Two ST-20 modules for Differential TDR or Single-ended TDT measurements
• Four ST-20 modules for differential TDT
• Calibration kit, which contains precision 50 ohm standards (Short, Load) for calibrated TDR
and S-parameter measurements (CALKIT-OSL)
• Either 2.92 mm (K-type) or 3.5 mm cables to connect to the DUT