Tektronix LTA7P Series, Руководство по обслуживанию

Страница: 79 / 172

Performance Verification: Ajustment/Verification Fixture
TLA7Nx, TLA7Px, & TLA7Qx Logic Analyzer Module Service Manual
4- 31
c. Set up the Trigger menu as follows:
H
Source CH2
H
Coupling DC
H
Slope +
H
Level 700 mV
H
Mode Normal
d. Set up the Measure menu as follows:
H
Select Measurement for CH1 Measure
H
Gating On
e. Set up the Cursor menu as follows:
H
Function V Bars
f. Set up the Acquire menu as follows:
H
Acquisition Mode Average 90
H
Repetitive Signal On
4. Connect CH2 of the oscilloscope to J4-2 on the adjustment/verification
fixture.
5.
Select Deskew from the Vertical menu of the oscilloscope.
NOTE
. Observe proper polarity when doing the following steps. See Figure 4--9
on page 4--23 to identify the ground side of the components being measured.
6.
Connect the CH1 probe of the oscilloscope to the custom probe tip adapter
and measure the signal across R85.
7. Use the large knob at the upper right of the oscilloscope panel to adjust delay
until the leading edges of the two waveforms coincide and the displayed
value of CH1-CH2 delay is averaged around 0
±
25 ps.
8. Move the CH1 probe to R321, R67, and R39 and press the Run/Stop button
to start an acquisition. Verify that the CH1-CH2 delay between any two
measurements does not exceed 90 ps.
9. The maximum difference between the three measured values represents the
channel-to-channel skew. Record this difference on the Calibration Data
Report.