Ublox ZOE-M8B Series, System Integration Manual

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ZOE-M8B - System Integration Manual
UBX-17045131 - R04 Contents Page 24 of 42
Production Information
2.11 Design-in checklist
2.11.1 General considerations
Check power supply requirements and schematic:
 Is the power supply voltage within the specified range? See how to connect power in Section 2.1
and section 0.
 Compare the peak current consumption of ZOE-M8B GNSS SiP with the specification of your
power supply.

GNSS receivers require a stable power supply. Avoid series resistance in your power supply line
(the line to
VCC
) to minimize the voltage ripple on
VCC
.
Backup battery
 For achieving a minimal Time To First Fix (TTFF) after a power down (warm starts, hot starts),
make sure to connect a backup battery to
V_BCKP , and use an RTC. If not used, make sure
V_BCKP is connected to neighbor pin G9.
Antenna/ RF input
 Make sure the antenna is not placed close to noisy parts of the circuitry and not facing noisy parts.
(e.g. micro-controller, display, etc.)
 Make sure your RF front end is chosen according your design, see section 2.5.
☞
For more information dealing with interference issues see the
GPS Antenna Application Note [4]
2.11.2 Schematic design-in for ZOE-M8B GNSS SiP
For a minimal design with the ZOE-M8B GNSS SiP, the following functions and pins need to be
considered:
•
Connect the power supply to VCC and V_BCKP .
•
Ensure an optimal ground connection to all ground pins of the ZOE-M8B GNSS SiP.
•
Choose the required serial communication interfaces (UART, 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 and add
RTC circuit.
2.12 Layout design-in checklist
Follow this checklist for the layout design to get an optimal GNSS performance.
Layout optimizations (see Section 2.13)
 Is the ZOE-M8B GNSS SiP placed according to the recommendation in section 2.13.3?
 Is the grounding concept optimal?

Are all the GND pins well connected with GND?
 Has the 50
Ω
line from antenna to SiP (micro strip / coplanar waveguide) been kept as short as
possible?
 Assure low serial resistance in VCC power supply line (choose a line width > 400 µm).
 Assure all VCC pins are well connected with power supply line.
 Keep power supply line as short as possible.
 Design a GND guard ring around the optional RTC crystal lines and GND below the RTC circuit.