User's Guide

2.2 Operating frequency bands 9
that no voltage higher than V3P3_LDO is presented to any GPIO. This may happen when powering
external devices, that connect to SoM module, from a boost converter.
Figure 2.2: Block diagram of the Core module.
2.2 Operating frequency bands
2.2.1 EU 863-870MHz ISM Band
In the European region the EN300220-2 V3.1.1 (2017-02) regulation defines the allowed frequency
allocation and spectrum access. Every device working in this band must comply with these rules
as shown in the Table 2.3. EU regulations restrict the maximum radiated power as well as the duty
cycle of the transmission in different frequency bands.To comply with the duty cycle requirement the
transmitting device must wait after every transmitted packet. The time device has to wait depends
on the time on air of transmitted packet and this in turn depends on the length of the packet and
spreading factor SF. This relation and required wait time can be seed in Table 2.2 According to
LoRaWAN specification every device has to implement at least 3 channels as follows:
• 868.10 MHz
• 868.30 MHz
• 868.50 MHz
The SoM is preconfigured to work with the MatchX Box gateway and additionally to the 3 mandatory
channels 5 additional channels are defined. The list of all preconfigured channels can be found in
Table 2.4.
2.2.2 US 902-928MHz ISM Band
These frequencies band can be used in USA, Canada and all other countries that adopt the entire
FCC-Part15 regulations in 902-928 ISM band. For these region MatchX uses predefined frequencies