U3280M_07 ATMEL [ATMEL Corporation], U3280M_07 Datasheet - Page 14

• Manufacturer Part Number: U3280M_07
• Description: Transponder Interface for Microcontroller
• Manufacturer: ATMEL [ATMEL Corporation]

14
U3280M
The antenna coil must be connected with a capacitor as a parallel LC resonant circuit to the Coil
1 and Coil 2 pins of the IC. The resonance frequency f
range of 100 kHz to 150 kHz.
The correct LC combination can be calculated with the following formula:
Figure 5-1.
Example: Antenna frequency: f
L
L
A
A
=
=
----------------------------------------------- -
C
-------------------------------------------------------------------------- -
2.2 nF
A
2
1
Antenna Circuit Connection
2
1
f
0
2
125 kHz
2
0
=
= 125 kHz, capacitor: C
737 µH
L
A
C
A
Coil 1
Coil 2
0
A
of the antenna circuit should be in the
= 2.2 nF
4688D–RFID–03/07