Why Incorrect Terminations Could Damage Your Device
Choosing wrong terminations may cause your device to output voltage
levels that are not as expected. It may also cause excessive current or
current flow in the wrong direction, which can damage your device.
Note that an internal protection algorithm becomes active if both the
termination voltage is wrongly adjusted
and
the termination voltage is
below +1.5 V. The protection algorithm sets the output voltages to safe
levels:
•
V
high
= termination v1 V
•
V
low
= termination v0.9 V
•
termination voltage remains unchanged
AC Coupling and Bias Tees
The pattern generator's outputs are normally DC-coupled; even when
AC
termination is selected. For this reason, extreme caution must be
taken when connecting your instrument to a device or test setup.
The diagram below shows a device that is
AC
coupled. Notice that the
capacitor is part of the test setup.
You can use an external bias network (also known as a
bias tee
) to power
your device. You must ensure, however, that the network is oriented
correctly. If it is not, damage may occur to your device or instrument.
The diagram below shows a
bias tee
that is positioned correctly. Notice
that the pattern generator's outputs are protected by the blocking
capacitor.
3
Setting up the Pattern Generator
76
Agilent J-BERT N4903 High-Performance Serial BERT
Summary of Contents for J-BERT N4903
Page 1: ...S Agilent J BERT N4903 High Performance Serial BERT User Guide s Agilent Technologies...
Page 68: ...2 Setting up Patterns 68 Agilent J BERT N4903 High Performance Serial BERT...
Page 158: ...4 Setting up the Error Detector 158 Agilent J BERT N4903 High Performance Serial BERT...
Page 314: ...6 Evaluating Results 314 Agilent J BERT N4903 High Performance Serial BERT...
Page 374: ...7 Jitter Tolerance Tests 374 Agilent J BERT N4903 High Performance Serial BERT...
Page 394: ...8 Solving Problems 394 Agilent J BERT N4903 High Performance Serial BERT...
Page 434: ...Index 434 Agilent J BERT N4903 High Performance Serial BERT...
