ams AS3953 NFiC interface chip

The ams AS3953 interface chip offers a high-data-rate interface between an NFC device such as a smartphone and any host microcontroller with a standard serial peripheral interface (SPI).

Operating on energy harvested from an NFC reader’s RF emissions, the AS3953 NFiC (near field communications interface chip) requires no external power source and no more than one external component (a capacitor).

The AS3953 is fully compliant with NFC Forum specifications (NFCIP-1 target at 106 Kbps) and the ISO14443A industry standard (up to 848 Kbps, to Level 4). This means that it can be used in contactless smart cards and as an NFC Forum-compatible interface tag, and can establish instant communication with any NFC-enabled phone in close proximity (<10 cm).

The chip is expected to find uses in a wide variety of applications, including contactless passive programming of MCU-based systems, smart cards with displays, smart retail shelf labels, sensors and ultra-low-power data loggers, medical devices and secured NFC Bluetooth pairing.

It can also enable innovative new approaches to system designs by using an NFC-enabled smartphone as a display host and system controller for what would normally be stand-alone devices. This eliminates the requirement for the slave device to have its own display and processor.

The AS3953 features a configurable wake-up interrupt, enabling a zero-power system design while in shutdown. It also contains a complete analog front end, 1 KB of internal EEPROM and a 4-wire SPI with a 32-byte FIFO. The device can draw up to 5 mA of harvested energy from the external magnetic field, and includes an internal power management circuit that can supply harvested energy to the application. This makes the AS3953 suitable for use with battery-powered and portable microcontroller-based devices.