Agilent Technologies J-BERT N4903B, Руководство пользователя, Страница: 131 / 572

Input and Output Ports - Procedures
You have to do the following to set up the pattern generator's output ports:
Setting Logic Levels and Terminations
Before you can start sending signals to your device, you have to set the logic levels
and terminations:
1 From the
PG Setup
submenu, click the
Data Output
menu item to modify Data
and Aux Data and the
Clock/Trigger Output
menu item to modify Clock and
Trigger.
2
In the
Data Logic Level
list, select the logic family that is appropriate for the
data input of your device.
3
In the
Clock Logic Level
list, select the logic family that is appropriate for the
clock input of your device.
When you modify the
Logic Level
of an output, the instrument automatically
sets the appropriate voltage levels and the
Termination
voltage and enables
termination.
4 If necessary, change the termination voltage by entering a new value. You can
also use the front panel knob to change the value.
The logic level automatically changes to
Custom
.
C A U T I O N
Selecting the wrong terminations may damage your device. See “Why Incorrect
Terminations Could Damage Your Device” on page 129 .
5 Connect the DUT's input ports to the Serial BERT's output ports.
C A U T I O N
Do not apply external voltages to the pattern generator outputs. For more
information, see
“AC Coupling and Bias Tees” on page 130 .
Output ports of the pattern generator that are not connected to another device must
be terminated with 50 Ohm to prevent the Serial BERT from damage.
Note that for unconnected ports, an internal protection circuit automatically
reduces the output voltages to safe levels.
Setting up the Pattern Generator
4
Agilent J-BERT N4903B High-Performance Serial BERT 131