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Qorvo 1800MHz Small Cell RF Card Hardware User’s Guide
Hardware User’s Guide
5.3
Power Options
The power diagram in the previous section (Digital Isolation) is not the default configuration. It
shows the Qorvo card powered with an external 5V supply. For demonstrations and development
it is mostly convenient to not have a second power supply and to
power the Qorvo card directly
from the ZCU111. This is the default configuration
and in this case DGND and RGND are not
separated, but are connected through a resistor,
R140, which must be removed for any the
“external power” configuration
.
The diagram below shows the default configuration, where the Qorvo card is powered from the
ZCU111 and R140 and R141 are placed. Note that since DGND and RGND are connected, much
of the isolation is effectively lost. In this case 5V is generated by an on-board buck converter and
LDO.
Figure 7
– Factory Default Configuration with 12V from the ZCU111
It is also possible to power the Qorvo card stand-alone on the bench, from either 12V or 5V. The power
options all require various resistor configurations. The table on sheet 11 of the schematic [2] clearly
specifies which resistors need to be placed or removed for each option.
Figure 8
– Possible Power Configurations
