آر اف (فرکانس رادیویی) و بی‌سیم آی‌سی آر‌اف‌آی‌دی و کنترل دسترسی

Product Attributes

Introduction

Si522A is a highly integrated NFC front- end for contactless communication at 13.56MHz, and supports automatic carrier detection function (ACD). Reader/Writer mode supporting ISO/IEC 14443A. The Si522A's internal transmitter part is able to drive a reader/writer antenna designed to communicate with ISO/IEC 14443A cards and transponders without additional active circuitry. The receiver part provides a robust and efficient implementation of a demodulation and decoding circuitry for signals from ISO/IEC 14443A compatible cards and transponders. The digital part handles the complete ISO/IEC 14443A framing and error detection (Parity and CRC). In ACD mode, the chip is mostly in sleep mode and woken up by 3K RC at a fixed time. It detects a 13.56MHz RF field and RF card with extremely low power consumption, and automatically generates interrupts to wake up the MCU when the field or card is detected. The functions of the detection field and card can be enabled separately. Under a typical 500ms polling cycle, the current is approximately 3.4uA. The entire ACD process does not require MCU intervention. Various host controller interfaces are implemented: SPI interface Serial UART (similar to RS232 with voltage levels according pad voltage supply) I2C interface.

Features

• Highly integrated analog circuitry to demodulate and decode responses
• Buffered output drivers for connecting an antenna with the minimum number of external components
• Typical operating distance in Read/Write mode up to 50 mm depending on the antenna size and tuning
• Supports ISO/IEC 14443 A with higher transmission rates communication, up to 848 kBd
• Supported host interfaces:
  • SPI up to 10 Mbit/s
  • I2C interface up to 400 kBd in fast mode, up to 3400 kBd in high-speed mode
  • Serial UART up to 1228.8 kBd
• FIFO buffer handles 64 byte send and receive
• Flexible interrupt modes
• Hard reset with low power
• Power-down by software
• Programmable timer
• Internal oscillator for connection to 27.12 MHz quartz crystal
• 2.5 V to 3.6 V power supply
• CRC coprocessor
• Programmable I/O pins
• Support ACD mode
• ACD mode supports for automatic detection of RF and cards
• ACD process without MCU intervention
• OSC vibration failure monitoring