14-17
IM 704510-01E
Troubleshooting and Maintenance
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Testing the Pulse Width Measurement
Instruments Required
Prepare the following instruments.
Synthesized signal generator
• Frequency range:
10 MHz to 90 MHz or higher
• Output level:
720 mV
rms
or higher
• Output level accuracy:
1.5 dB or better
• Recommended instrument: 8657B Synthesized signal generator or equivalent (by
Agilent Technologies)
The procedure for testing the pulse width measurement using the recommended
instruments is described below.
Connecting the Instruments
• Check that the power switch is turned OFF on all instruments before connecting the
instruments.
• Connect the output of the synthesized signal generator to the input terminal (CH A/CH
B) of the TA720.
TA720
8657 B
10MHz REF IN
REFERENCE OUT
OUTPUT
CH B
CH A
Synthesized signal generator
(8657B)
Instrument Settings
• TA720
• Sampling mode: Hardware histogram mode
• Input settings:
DC coupling, 50
Ω
(both CH A and CH B), trigger level = 0 V
• Function:
Pulse width A, B
• Gate:
Event, 1000000
• Reference:
External
• X Center, X Span:
Input Frequency
X Center
X Span
10 MHz
50 ns
15 ns
83.3 MHz
6 ns
15 ns
• Y High:
10
6
• 8657B
• Frequency:
10 MHz, 83.3 MHz
• Level:
360 mV
rms
Test Method
• Test the TA720 after 30 minutes of warm-up.
• Set the frequency of the 8657B to the values given in the table below, and check that
the measured values (mean value and standard deviation) are within the allowable
range using the pulse width measurement function on the TA720. Perform the same
test on both CH A and CH B.
14.6 Performance Test