SI522A 13.56MHz contactless reader-writer chip

The Si522A is A highly integrated, contactless reader chip operating at 13.56MHz. The reader supports ISO/IEC 14443 A and supports automatic carrier detection (ACD).

The Si522A's internal transmitter drives the reader antenna to communicate with the ISO/IEC 14443 A card and transponder without the need for additional peripheral circuitry. The receiver module provides a powerful and reliable circuit for demodulation and decoding of ISO/IEC 14443A compatible card and transponder signals. The digital module handles full ISO/IEC 14443 A-frames and error detection functions (parity and CRC).

In ACD mode, the chip is dormant for most of the time and wakes up regularly by 3K RC to detect the 13.56MHz RF field and RF card with ultra-low power consumption, and the detection scene or card automatically generates an interrupt to wake up the MCU. Detection field and card functions can be enabled separately. On a typical 500ms polling cycle, the current is about 3.4uA. The entire ACD process does not require MCU intervention.

The chip implements a variety of host interfaces:

- SPI interface with a rate of up to 10Mbits/s

- Standard dual-wire serial interface, fast mode speed up to 400kBd, high-speed mode speed up to 3400kBd

- Serial UART, speed up to 1228.8kB

Package: QFN32/5 *5*0.8m

Product characteristics

• Highly integrated analog circuits for demodulation and decoding

• Buffered output driver with minimal peripheral components for antenna connection

• The operating distance of the reader mode depends on the size and number of turns of the antenna, the typical operating distance is 50mm,

• Supports ISO/IEC 14443 A higher rate communication up to 848kBd

· Supported host interfaces:

SPI interface, speed up to 10Mbits/

I²C interface, fast mode speed up to 400kBd, high-speed mode speed up to 3400kBd

Serial UART up to 1228.8kB

· 64-byte FIFO

· Flexible interrupt mode

· Low power hard reset function

· Support soft power failure mode

· Integrated programmable timer

·27.12MHz internal oscillator

· Supply voltage 2.5V-3.6V

· Integrated CRC coprocessor

· Programmable I/O pin

· Support ACD mode

- The ACD mode automatically detects the 13.56MHz RF field and RF card

- The ACD process does not require MCU intervention

- OSC Indicates the function of monitoring startup failure

Applications:

Smart door lock、 smart payment system.