There is a 64-VFQFN Exposed Pad package on the board that RF transceiver IC is used to save space. With transceiver RF's high efficiency and reliable performance, it emerges as a TxRx + MCU.A high level of reliability is provided by using an advanced transceiver RF' packaging Tray.Try searching for ATMEGA128 variants of the transceiver.In the 2.4GHz frequency range, RF transceiver operates .
ATMEGA128RZAV-8MU Features
64-VFQFN Exposed Pad package TxRx + MCU Tray is used Use ATMEGA128
ATMEGA128RZAV-8MU Applications
There are a lot of Microchip Technology ATMEGA128RZAV-8MU RF Transceiver ICs applications.