NINA-B2 series - System integration manual
UBX-18011096 - R05
Design-in
Page 17 of 35
C1- Public
3
Design-in
3.1
Overview
For an optimal integration of NINA-B2 series modules in the final application board, it is recommended
to follow the design guidelines stated in this chapter. Every application circuit must be properly
designed to guarantee the correct functionality of the related interface; however, several points
require high attention during the design of the application device.
The following list provides important points sorted by rank of importance in the application design,
starting from the highest relevance:
1.
Module antenna connection:
Ant
pad
Antenna circuit affects the RF compliance of the device integrating NINA-B221 modules with
applicable certification schemes. Follow the schematic and layout design recommendations
described in
2.
Module supply:
VCC
,
VCC_IO
, and
GND
pins
The supply circuit affects the performance of the device integrating NINA-B2 series module.
Follow the schematic and layout design recommendations described in
3.
High speed interfaces:
UART
pins
High speed interfaces can be a source of radiated noise and can affect compliance with regulatory
standards for radiated emissions. Follow the schematic and layout design recommendations
described in
Asynchronous serial interface (UART) design
4.
System functions:
RESET_N
,
GPIO
and other
System input and output pins
Accurate design is required to guarantee that the voltage level is well defined during module boot.
Other pins: Accurate design is required to guarantee proper functionality.
3.2
Supply interfaces
Module supply (VCC) design
Good connection of the module’s VCC pin with DC supply source is required for correct RF
performance. The guidelines are summarized below:
•
The VCC connection must be as wide and short as possible.
•
The VCC connection must be routed through a PCB area separated from sensitive analog
signals and sensitive functional units. It is a good practice to interpose at least one layer of the
PCB ground between VCC track and other signal routing.
There is no strict requirement of adding bypass capacitance to the supply net close to the module.
But depending on the layout of the supply net and other consumers on the same net, bypass
capacitors might still be beneficial. Though the GND pins are internally connected, connect all the
available pins to solid ground on the application board, as a good (low impedance) connection to an
external ground can minimize power loss and improve RF and thermal performance.
Digital I/O interfaces reference voltage (VCC_IO)
Good connection of the module’s VCC_IO pin with DC supply source is required for correct
performance. The guidelines are summarized below:
•
The VCC_IO connection must be as wide and short as possible.
•
The VCC_IO connection must be routed through a PCB area separated from sensitive analog
signals and sensitive functional units. It is a good practice to interpose at least one layer of
PCB ground between VCC_IO track and other signal routing.
