nRF5340 v2.0.2

NFC antenna interface

The nRF5340 DK supports a Near Field Communication (NFC) tag.

NFC-A Listen Mode operation is supported on the nRF5340 System on Chip (SoC). The NFC antenna input is available on connector J5 on the nRF5340 DK.

Figure 1. NFC antenna connector
NFC antenna connector on the nRF5340 DK

NFC uses two pins, NFC1 and NFC2, to connect the antenna. These pins are shared with General-Purpose Input/Output (GPIO)s (P0.02 and P0.03). The PROTECT field of the NFCPINS register in User Information Configuration Registers (UICR) defines the usage of these pins and their protection level against abnormal voltages. The content of the NFCPINS register is reloaded at every reset.

Configuring NFC pins as GPIOs

The NFC pins are enabled by default. NFC can be disabled and GPIOs enabled by setting the CONFIG_NFCT_PINS_AS_GPIOS to y. See Configuring your application for instructions.
Pins P0.02/NFC1 and P0.03/NFC2 are by default configured to use the NFC antenna. To use these pins as GPIO, R43 and R46 must be not connected (NC) and R42 and R45 must be shorted with an OR resistor.

Figure 2. NFC input
Schematic: NFC input