User guide

Note that an internal protection circuit becomes active if the termination voltage
is wrongly adjusted. The protection circuit sets the output voltages to safe levels,
typically:
Vhi = Vlo = Vterm = externally measured termination voltage.
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.
4 Setting up the Pattern Generator
130 Agilent J-BERT N4903B High-Performance Serial BERT