Manual

ZOE-M8 series - Hardware Integration Manual
UBX-16030136 - R07 Production Information Design-in
Page 18 of 32
2.10 Design-in checklist
2.10.1 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 2.9.
 Compare the peak current consumption of ZOE-M8 GNSS SiPs 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 [3]
2.10.2 Schematic design-in for ZOE-M8 GNSS SiPs
For a minimal design with the ZOE-M8 GNSS SiPs, the following functions and pins need to be considered:
• Connect the power supply to VCC and V_BCKP.
• If you use DC/DC converter on the ZOE-M8Q, ensure the external inductor and capacitor are in place in
between V_DCDC_OUT and V_CORE.
• Ensure an optimal ground connection to all ground pins of the ZOE-M8 GNSS SiPs.
• 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 an RTC circuit.
2.11 Layout design-in checklist
Follow this checklist for the layout design to get an optimal GNSS performance.
Layout optimizations (see Section 2.12)
 Is the ZOE-M8 GNSS SiP placed according to the recommendation in section 2.12.3?
 Is the grounding concept optimal?
 Are all the GND pins well connected with GND?
 Has the 50 Ohm line from the antenna to the 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 the power supply line.
 Keep the power supply line as short as possible.
 If DC/DC is used on the ZOE-M8Q, ensure the inductor and capacitor are connected close to the ZOE-M8Q
V_CORE and V_DCDC_OUT pins and the capacitor has a good GND connection.
 Design a GND guard ring around the optional RTC crystal lines and GND below the RTC circuit.