NINA-B1 series - System Integration Manual
UBX-15026175 - R06
System description
Page 11 of 48
When using NINA-B1 with a battery, the I/O voltage level will vary with the battery output voltage, depending on
the charge of the battery. Level shifters might be needed depending on the I/O voltage of the host system.
1.3.3
VCC application circuits
The power for NINA-B1 series modules is provided through the VCC pins, which can be one of the following:
•
Switching Mode Power Supply (SMPS)
•
Low Drop Out (LDO) regulator
•
Battery
The SMPS is the ideal choice when the available primary supply source has higher value than the operating
supply voltage of the NINA-B1 series modules. The use of SMPS provides the best power efficiency for the overall
application and minimizes current drawn from the main supply source.
While selecting SMPS, ensure that AC voltage ripple at switching frequency is kept as low as
possible. Layout shall be implemented to minimize impact of high frequency ringing.
The use of an LDO linear regulator is convenient for a primary supply with a relatively low voltage where the
typical 85-90% efficiency of the switching regulator leads to minimal current saving. Linear regulators are not
recommended for high voltage step-down as they will dissipate a considerable amount of energy.
DC/DC efficiency should be evaluated as a tradeoff between active and idle duty cycle of the specific application.
Although some DC/DC can achieve high efficiency at extremely light loads, a typical DC/DC efficiency quickly
degrades as idle current drops below a few mA greatly reducing the battery life.
Due to the low current consumption and wide voltage range of the NINA-B1 series module, a battery can be
used as a main supply. The capacity of the battery should be selected to match the application. Care should be
taken so that the battery can deliver the peak current required by the module. See the
NINA-B1 series Data
Sheet [2]
for electrical specifications.
It is considered as best practice to have decoupling capacitors on the supply rails close to the NINA-B1 series
module, although depending on the design of the power routing on the host system, capacitance might not be
needed.
1.4
System function interfaces
1.4.1
Module reset
You can reset the NINA-B1 modules by applying a low level on the
RESET_N
input pin, which is normally set
high with an internal pull-up. This causes an “external” or “hardware” reset of the module. The current
parameter settings are not saved in the non-volatile memory of the module and a proper network detach is not
performed.
1.4.2
Internal temperature sensor
The radio chip in the NINA-B1 module contains a temperature sensor used for over temperature and under
temperature shutdown.
The temperature sensor is located inside the radio chip and should not be used if an accurate
temperature reading of the surrounding environment is required.
1.5
Debug – Serial Wire Debug (SWD)
The primary interface for debug is the SWD interface. The SWD interface can also be used for firmware upgrade.
The two pins,
SWDIO
and
SWDCLK
should be made accessible on header or test points.
