NINA-B50 series - Hardware integration manual
UBX-22021116 - R02
Design-in
Page 19 of 57
C1-Public
3
Design-in
Follow the design guidelines in this chapter to optimize the integration of NINA-B50 series modules
in the final application board.
3.1
Overview
All application circuits must be properly designed, but several points require special attention during
the application design. In an order of importance:
•
Module antenna connection:
ANT
pad RF transmission lines connecting the
ANT
pad with the
related antenna connector or antenna, must be designed with a 50
impedance characteristic.
See also
•
Module supply:
VCC
,
VCC_IO
, and
GND
pins.
Supply circuits can affect the RF performance. It is important to observe the schematic and layout
design for these supplies. See also
. Select appropriate power supply
source and bypass capacitors and carefully route the power supply nets or planes. Modules
normally include several supply pins described in the pin out of the NINA-B50 series data sheet
•
High-speed interfaces:
LPUART, LPSPI, LPI2C
pins.
High-speed interfaces are a potential source of radiated noise that can affect the regulatory
compliance standards for radiated emissions. It is important to follow the schematic and layout
design recommendations described in the
•
System functions:
RESET_N
, GPIO and other System input and output pins
Careful utilization of these pins in the application design is required to guarantee for correct boot
up and system operation. Ensure that the voltage level is correctly defined during module boot. It
is important to follow the schematic and layout design recommendations described in the
•
Other pins:
ADC
,
I2S, QDEC,
and NC pins.
Careful utilization of these pins is required to guarantee proper functionality. It is important to
follow the schematic and layout design recommendations described in the
3.2
RF interface
As the unit cannot be mounted arbitrarily, the placement should be chosen with consideration so that
it does not interfere with radio communication. NINA-B506 modules include an internal PCB trace
antenna, which makes them unsuitable for mounting in a metal enclosure. No metal casing or plastics
using metal flakes should be used. Avoid metallic based paint or lacquer as well. NINA-B501 modules
offer more freedom as an external antenna can be mounted further away from the module.
⚠
According to the FCC regulations, the transmission line from the m
odule’s antenna pin to the
antenna or antenna connector on the host PCB is considered part of the approved antenna design.
Therefore, module integrators must either follow exactly one of the antenna reference designs
used in the module’s FCC type approval
or certify their own designs.
3.2.1
Antenna integration
At the start the application design phase, when the mechanical design and the physical dimensions
of the board are still under analysis/decision, the antenna integration shall be considered. Apart from
the product’s performance
, the compliance and subsequent certification of the RF design depends
heavily on the radiating performance of the antennas.
