R&S AFQ100A Operating Manual page 173

R&S AFQ100B
Interface Port
Notes on connecting an output device on Port1 and Port 2!
- the LVDS output is held higher than 0.6 V
The output common-mode voltage is not properly established if the LVDS output is
held higher than 0.6V when the R&S AFQ is switched on.
As consequence, the output will not work properly.
- the common mode voltage is held higher than 2.5 V
Even if the the common mode voltage is applied for only a very short time, the output will back off.
Example:
If a DUT has pullups to 3V3 on both LVDS lines, it will pull these lines to 3V3. When the DUT is
now connected to the AFQ, the AFQ will see this 3V3, at least for short time.
Countermeasure:
Power Up the DUT after powering the R&S AFQ.
In both cases the output of the R&S AFQ will not be damaged and will return to work after
reinitializing.
Note:
To avoid electromagnetic interference (EMI) only the cable R&S SMU-Z6 must be used for the
connection to the digital interface.
The associated cable is available under R&S part number 1415.0201.02
1410.9069.32
Selects one of the two available digital interfaces (see
chapter 1, section
chapter 8, section
Interfaces"). Depending on the selected port the
output dialog changes.
The interface PORT1 at the front panel of the
1
instrument is selected (R&S Standard).
(R&S Standard)
Remote-control command:
SOUR:OUTP:DIG:PORT PORT1
The interface PORT2 at the front panel of the
2
instrument is selected (parallel port, LVDS standard).
(Parallel, LVDS)
Remote-control command:
SOUR:OUTP:DIG:PORT PORT2
4.65
Output Block
"Legend for Front Panel
"Specification of Digital
View" and
E-3