
Elatec GmbH
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2.3 Electrical Characteristics
Frequency
13.56MHz
Power supply
4.5V - 5.5V DC
Current consumption
RF field off:
RF field on:
20mA
Typically 120mA, depending on antenna
2.4 External Connections
The schematic below shows a typical application circuit for operating the reader module.
2.4.1 Antenna
Nano Module Multi ISO requires an external antenna circuit for reading transponders. The part values
of C1
– C5 and R1 are strongly depending on the used antenna inductor. Take the guide below as a
reference for creating your own PCB antenna.
Little PCB Antenna Design Guide:
-
Antenna inductance value is usually in the range of 1µH.
-
For antenna loop up to 40mm diameter use 5 turns.
-
For antenna loop larger than 40mm diameter use 3 turns.
-
Use between 1mm to 2mm track width.
-
Middle tap improves EMC compliance, but can be omitted for simple designs.
-
All capacitors have to be chosen to create maximum field strength (measure antenna field with
an oscilloscope and the voltage induced in some auxiliary loop; alternatively measure the
module power consumption which is maximum at optimum tuning).
-
C1 is used for fine tuning. Some extra capacitors may be connected in parallel to achieve best
performance.
-
Typical capacitor values: 10pF … 470pF. Prefer NP0/C0G ceramic capacitors.
-
Value of R1 is usually 4.7k
Ω, but this value may differ from design to design.
For further information regarding antenna design please contact NXP in order to receive the
appropriate Application notes (Application Note Micore Reader IC Family; Directly Matched Antenna
Design)