nRF5340 PDK v1.0.0

NFC antenna interface

The nRF5340 PDK 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 PDK.

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

NFC uses two pins, W1 (NFC1) and AA1 (NFC2), to connect the antenna. These pins are shared with GPIOs (P0.02 and P0.03) and the PROTECT field in the NFCPINS register in 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.

Note: The NFC pins are enabled by default.

NFC can be disabled and GPIOs enabled by defining the CONFIG_NFCT_PINS_AS_GPIOS variable in the project settings. The way of doing this depends on the Integrated Development Environment (IDE)/toolchain in use:

Pins W1 and AA1 are by default configured to use the NFC antenna, but if they are needed as normal GPIOs, R43 and R46 must be NC and R42 and R45 must be shorted by 0R.

Figure 2. NFC input
Schematic: NFC input