AN2972 Datasheet, PDF (1/25 Pages) STMicroelectronics – Designing an antenna for the M24LRxx-R

AN2972
Application note
Designing an antenna for the M24LRxx-R and M24LRxxE-R
dual interface I²C/RFID devices
Introduction
The M24LRxx-R or M24LRxxE-R device is an EEPROM designed for access via two
different interfaces: a wired I²C interface and a standard contactless ISO 15693 RFID
interface.
Figure 1. Dual interface EEPROM
Note:
Both interfaces are widely used industry standards. The M24LRxx-R or M24LRxxE-R can
be integrated into almost any electronic application, provided that the processor offers an
I²C interface. It may also be accessed by any RFID reader that supports the ISO 15693
interface.
The purpose of this application note is also to:
● explain the basic principle of passive RFID
● describe the basics of a 13.56 MHz inductive antenna design
● provide some guidelines for a successful integration, from design to production.
Table 1 lists the products concerned by this application note.
Table 1. Applicable products
Type
Applicable products
Dual interface EEPROMs
Evaluation boards
M24LRxx-R, M24LRxxE-R
ANTx-M24LRxxx, M24LR-Discovery, ROBOT-M24LR16E-A
STEVAL-IHP004V1, STEVAL-IPR002V1, STEVAL-IPE020V1
The standard M24LRxx-R and energy-harvesting M24LRxxE-R devices will be referred to
as M24LRxx devices throughout the document.
December 2012
Doc ID 15629 Rev 6
1/25
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