Overview
An access, a ticketing or a secure-identity product needs a contactless front end and, where the transaction or the identity matters, a secure element to hold the key. NXP pioneered NFC and provides both the reader ICs and the EdgeLock secure element, and BeiLuo supplies them with genuine traceability and FAE support. This page shows how the reader and the secure element fit together in an NFC and access design.
The Contactless Front End
The reader IC generates the 13.56 MHz field, modulates the command to the card and demodulates and decodes the response, so it is the heart of the contactless interface. The NXP MFRC522 is a widely used reader for ISO/IEC 14443A and MIFARE, with SPI, I2C and UART host interfaces, and it suits a low-cost access, a ticketing or an identification reader. The NXP PN532 is a full NFC controller with an 80C51 core and firmware for the reader and the writer, the card emulation and the peer-to-peer modes, and it supports ISO/IEC 14443A and MIFARE, FeliCa and the NFCIP-1 standard, so it suits a product that must do more than read a card.
Choosing the Reader
Choose the MFRC522 for a simple, low-cost reader and the PN532 for a full NFC front end with the peer-to-peer and the card modes. Both connect over SPI, I2C or UART, so the host interface follows the microcontroller. Confirm the cards and the protocols the application must handle.
The Antenna
The 13.56 MHz antenna and its matching network decide the read range and the tuning, so they are part of the design, not a detail. Follow the NXP antenna and RF design guide, keep the matching components close to the IC, keep the loop clean and confirm the tuning on the bench with a reference card. A poorly matched antenna is the usual cause of a short read range.
Layout of the RF Section
Keep the RF section away from the noisy digital nodes, use a clean ground under the matching network and keep the trace to the antenna short and balanced. The RF layout decides the range, so give it the space it needs.
The Secure Element
Where the transaction or the identity must be trusted, an NXP SE050 EdgeLock secure element stores the keys in tamper-resistant hardware and performs the cryptographic operations there, so the secret is never exposed in the main processor. It connects over the I2C bus, so it is easy to place beside the reader or the host, and it provides a root of trust for a secure boot, an authentication or a secure connection. Plan the key provisioning and the certificate chain early, because they decide the security of the product.
A Secure Transaction
In a payment or an access terminal the reader handles the contactless link and the secure element handles the cryptography, and the two together provide a secure transaction. Use the power switch and the secure interface the reader provides for the companion chip.
Verification
Validate the design on the bench by measuring the read range and the tuning with reference cards, by checking the host interface and the interrupt and by confirming the secure element operation against the provisioning scheme. Our FAE team can review the RF layout and the security plan and help you interpret the measurements.
Getting Help
Send your cards and protocols, the read range, the host interface and the security requirement to our FAE team, and we will propose a reader and a secure element, help choose the interface and the antenna and review the layout and the security. BeiLuo holds mainstream NXP devices in regional stock and ships them with an import declaration, a certificate of origin and a RoHS compliance file, so an NFC and access design can move from prototype to production without a supply gap.