MFRC63002R datasheet(105/118 Pages) NXP

105 / 118 page

MFRC630

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Product data sheet

COMPANY PUBLIC

Rev. 3.1 — 6 September 2012

227531

105 of 118

NXP Semiconductors

MFRC630

Contactless reader IC

14.1.4 Antenna coil

The precise calculation of the antenna coils’ inductance is not practicable but the

inductance can be estimated using the following formula. We recommend designing an

antenna either with a circular or rectangular shape.

(4)

• I1 - Length in cm of one turn of the conductor loop

• D1 - Diameter of the wire or width of the PCB conductor respectively

• K - Antenna shape factor (K = 1,07 for circular antennas and K = 1,47 for square

antennas)

• L1 - Inductance in nH

• N1 - Number of turns

• Ln: Natural logarithm function

The actual values of the antenna inductance, resistance, and capacitance at

13.56 MHz depend on various parameters such as:

• antenna construction (Type of PCB)

• thickness of conductor

• distance between the windings

• shielding layer

• metal or ferrite in the near environment

Therefore a measurement of those parameters under real life conditions, or at least a

rough measurement and a tuning procedure is highly recommended to guarantee a

reasonable performance. For details refer to the above mentioned application notes.

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MFRC63002R Datasheet(PDF) 105 Page - NXP Semiconductors