Datasheet

APPLICATION SPECIFICATION
REVISION:
ECR/ECN INFORMATION:
TITLE:
Rectangular Standard NFC Antenna
Application Specification
SHEET No.
B1
EC No:
626150
8 of 21
DATE:
2019/10/23
DOCUMENT NUMBER:
CREATED / REVISED BY:
CHECKED BY:
APPROVED BY:
AS-1462360001
Liu Hai 2019/10/17
Cheng Kang 2019/10/17
Stary Song 2019/10/17
TEMPLATE FILENAME: APPLICATION_SPEC[SIZE_A](V.1).DOC
5.0 MATCHING NETWORK DESRICPTION
The matching network will depend on the selected NFC antenna and the NFC chipset. When
customers use the NFC antenna, they should change the matching network according to the
actual application environment. During the detection distance test, in order to get good detection
distance, the NFC antennas have been well matched on the evaluation board with various
capacitor’s value. The below picture shows the matching network for the evaluation board while
the below table shows the reference capacitor values for each NFC antenna.
Note that the following matching is recommended for the TI evaluation board (model:
TRF7970AEVM). When implement into the system, the frequency resonant might be off-tune due
to the loading of surrounding components especially metal plane. This off-tune can be
compensated through matching. And when different chipset is used in the real system, the
matching circuit should be changed to match the chipset requirement.
FIGURE 5.1 MATCHING NETWORK ON THE EVALUATION BOARD