Tektronix TLA600 Series, Руководство по обслуживанию

Страница: 103 / 188

Adjustment/Verification Fixture Adjustment
5- 14
TLA600 Series Logic Analyzer Service Manual
e. Set up the Cursor menu as follows:
H
Function V Bars
f. Set up the Acquire menu as follows:
H
Acquisition Mode Sample
H
Repetitive Signal On
3. Move shorting jumpers at J16 to MIN PULSE. Connect the jumpers to pins
1--2, and pins 3--4.
a.
Connect the CH1 probe to J2--2. Measure the pulse width using the
vertical cursor bars.
b. Using the delay taps on Delay DATA PULSE ADJ, add or subtract the
appropriate delay to ensure a 1.9 ns (
±
50 ps) data pulse width. See Note
that follows.
NOTE
. The trace loops on the circuit board add delay according to their length.
The longer the loop, the more delay is added to the circuit.
The loops, from shortest to longest, add approximately 50 ps, 100 ps, 200 ps,
400 ps, and 800 ps respectively.
The length of the jumper wire also adds delay, so care should be used in the
length of the jumper wire you add.
It will be necessary to add small loops to the wire jumpers to obtain correct
delays and pulse widths on some of the following adjustments.
c. Move shorting jumpers at J16 to DESKEW. Connect the jumper to pins
4--5, and 2--3.
d. With the CH1 probe still connected to J2--2, measure the pulse width
using the vertical cursor bars.
e. Using the delay taps on Delay DESKEW PULSE ADJ add or subtract
the appropriate delay to ensure a 8--10 ns pulse width. See Note
following step b.