Calculators » NFC Tag Capacitance Calculator from Resonant Frequency

NFC Tag Capacitance Calculator from Resonant Frequency

nfc tag capacitance resonant frequency calculator formula

NFC systems rely on LC resonance for efficient energy transfer and communication. Proper tuning of the NFC antenna circuit requires accurate calculation of the tag capacitance based on resonant frequency and inductance. The NFC Tag Capacitance Calculator simplifies this critical design step.

NFC Tag Capacitance Calculator

INPUTS:

NFC Tag Resonant Frequency = 13.56 MHz
Antenna Inductance = 2 uH

OUTPUT:

Required Capacitance = 69 pF

NFC Resonant Circuit Basics

An NFC tag antenna forms a resonant LC circuit consisting of:

Inductance (L) from the antenna coil
Capacitance (C) from the chip and tuning capacitors

Maximum energy transfer occurs at the resonant frequency.

NFC Tag Capacitance Formula

NFC Capacitance Formula

As shown, resonant frequency formula for LC circuit is as follows.

f = 1/2*pi* sqrt(L*C)

Rearranging to solve for capacitance :

C = 1/((2*pi*f)^2 * L)

Summary:

The NFC Tag Capacitance Calculator determines the required capacitance of an NFC tag using its resonant frequency and inductance. This tool supports accurate antenna tuning, efficient energy transfer and optimal NFC performance. It is commonly used in NFC tag design, prototyping and validation to ensure reliable communication and maximum read range.