nRF21540 is an RF front-end module suitable for Bluetooth® Low Energy and IEEE 802.15.4 range extension.
Device features include a configurable gain power amplifier (PA) in the transmit path (TX) and a low noise amplifier (LNA) in the receive path (RX). Single-ended operation on both TRX and ANT1/2 ports is supported and requires four external components (for single antenna operation) for the RF path, plus antenna termination for the unused antenna port.
The device is controlled through a set of input pins. Alternatively, the device can be controlled by writing to internal control registers through the SPI interface. The two antenna ports enable applications using antenna diversity and can be selected using pin ANT_SEL.
Highly configurable gain in Transmit state enables the application to implement adaptive gain control algorithms.
Gain settings can be stored for factory device calibration to user configurable output power through on-board non-volatile memory.