Best NFC Microcontrollers (MCUs) & Integrated Chips

Introduction : As contactless technology becomes a core feature in smart devices, NFC microcontroller units (MCUs) and integrated NFC chips are gaining widespread adoption across IoT, consumer electronics, automotive systems and secure authentication applications. These specialized chips combine processing power with built-in NFC functionality, reducing system complexity, cost and power consumption.

What is NFC compliant MCU?

An NFC Compatible MCU is the processing unit (the “brain”) responsible for managing the logic, protocol stack, and data interpretation of an NFC system. There are two primary architectural approaches viz. General Purpose MCU and Integrated NFC MCU (SoC).

1. General Purpose MCU: A standard microcontroller (e.g. STM32, MSP430, ESP32) that connects to an external NFC Transceiver via a digital interface (SPI/I2C). The MCU runs the NFC software stack.

2. Integrated NFC MCU (SoC): A single chip that combines the processor core and the RF transceiver/tag frontend in one package. This is common for space-constrained devices like smart cards or key fobs.

The core functions of NFC compatible MCU are as follows.

• Protocol Stack Management
• NDEF Parsing & Generation
• Cryptographic Operations : For secure applications (Type 4 Tags, Passports, Payment), the MCU performs AES/DES encryption and Mutual Authentication to unlock protected memory sectors on a tag.
• Hardware Control: It manages the GPIO pins to enable/disable the transceiver (for power saving).
• Application Logic: It decides the outcome of a scan.

Key Specifications for Selection

1. Memory Size (Flash & RAM) : For flash memory, minimum of 64KB is recommended for a full Reader/Writer stack. For RAM, minimum of 8KB to 16KB is recommended.
2. Digital interfaces : SPI, I2C, USB etc.
3. Cryptographic Accelerators (Hardware Security) support
4. Power Consumption & Wake Up Sources : Look for MCUs with deep sleep modes and fast wake-up.
5. Choose a manufacturer that provides a Certified NFC Library middleware

MCUs with integrated NFC reader

MCUs with Integrated NFC Tag

NFC Sensor Transponders

Popular MCUs for external NFC

Summary

NFC microcontrollers and integrated NFC chips offer a powerful all-in-one solution for contactless communication and embedded control. By combining an MCU with an NFC transceiver in a single package, these devices simplify hardware design, improve energy efficiency and accelerate product development.

References for further study

• STMicroelectronics. NFC/RFID Reader/Writer - Hardware and Software Design Guide.
• NXP Semiconductors. NFC Reader Library for Cortex-M Microcontrollers User Guide.
• Nordic Semiconductor. nRF52 Series - NFC Antenna Tuning and Design Guide.