NINA-B1 series - System Integration Manual
UBX-15026175 - R06
System description
Page 14 of 48
Table 6: Acquisition vs source impedance
1.7.1.2
Comparator
The comparator compares voltages from any analog pin with different references as shown in Table 7. It
supports full 0 V to VCC input range and can generate different software events to the rest of the system.
1.7.1.3
Low power comparator
The low-power comparator operates in the same way as the normal comparator, with reduced functionality. It
can be used during system OFF modes as a wake up source.
1.7.1.4
Analog pin options
The following table shows the supported connections of the analog functions.
An analog pin may not be simultaneously connected to multiple functions.
Table 7: Possible uses of analog pin
1.8
Antenna interfaces
The antenna interface is different for each module variant in the NINA-B1 series.
1.8.1
Antenna pin – NINA-B111
The NINA-B111 is equipped with an RF pin. The RF pin has a nominal characteristic impedance of 50
Ω
and must
be connected to the antenna through a 50
Ω
transmission line to allow reception of radio frequency (RF) signals
in the 2.4 GHz frequency band.
Choose an antenna with optimal radiating characteristics for the best electrical performance and overall module
functionality. An internal antenna, integrated on the application board or an external antenna that is connected
to the application board through a proper 50
Ω
connector can be used.
While using an external antenna, the PCB-to-RF-cable transition must be implemented using either a suitable
50
Ω
connector, or an RF-signal solder pad (including GND) that is optimized for 50
Ω
characteristic impedance.
1.8.1.1
Antenna matching
The antenna return loss should be as good as possible across the entire band when the system is operational to
provide optimal performance. The enclosure, shields, other components and surrounding environment will
ACQ [us]
Maximum source resistance [k
Ω
]
3
10
5
40
10
100
15
200
20
400
40
800
Analog function
Connects to
ADC single-ended input
Any analog pin or VCC
ADC differential input
Any analog pin or VCC pair
Comparator IN+
Any analog pin
Comparator IN-
Pin 24 or 25, VCC, 1.2 V, 1.8 V, 2.4 V
Low-power comparator IN+
Any analog pin
Low-power comparator IN-
Pin 24 or 25, 1/16 to 15/16 VCC in steps of 1/16 VCC
