ZED-F9T - Integration Manual
• Ensure the group delay variation including active antenna is 10 ns max @ each GNSS system
bandwidth. Note: Inter-signal requirement 50 ns max.
• ESD protection on the RF input is mandatory.
• Bias-t inductor must be L1 and L2 band frequency selected. 120 nH typical.
• Ensure RF trace is tuned for 50 Ω at 1575 MHz to ensure L1 and L2 bandwidth.
4.8.5 Ground pads
Ensure the ground pads under the module are connected to ground.
If a patch type antenna is used, an antenna ground plane with minimum 100 - 150 mm diameter
is required.
4.8.6 Schematic design
For a
minimal design
with the ZED-F9T GNSS modules, the following functions and pins need to
be considered:
• Connect the power supply to VCC and V_BCKP.
• V_USB: If USB is used connect V_USB to receiver VCC.
• If USB is not used connect V_USB to ground.
• Ensure an optimal ground connection to all ground pins of the ZED-F9T GNSS modules.
• Choose the required serial communication interfaces (UART, USB, SPI or DDC) and connect the
appropriate pins to your application.
• If you need hot or warm start in your application, connect a backup battery to V_BCKP.
• Antenna bias is required, see ZED-F9T antenna bias section.
4.8.7 Layout design-in guideline
• Is the ZED-F9T placed away from any heat source?
• Is the ZED-F9T placed away from any air cooling source?
• Is the ZED-F9T shielded by a cover/case to prevent the effects of air currents and rapid
environmental temperature changes?
• Is the ZED-F9T placed as recommended in the Layout and Layout Guidance section?
• Assure a low serial resistance on the VCC power supply line (choose a line width > 400 um).
• Keep the power supply line as short as possible.
• Add a ground plane underneath the GNSS module to reduce interference. This is especially
important for the RF input line.
• For improved shielding, add as many vias as possible around the micro strip/coplanar
waveguide, around the serial communication lines, underneath the GNSS module, etc.
UBX-19005590 - R01
4 Design
Page 71 of 80
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