The AT86RF231-ZU is a 2.4GHz Low-power Transceiver, true SPI-to-antenna solution providing a complete radio transceiver interface between the antenna and the microcontroller. It comprises the analog radio transceiver and the digital demodulation including time and frequency synchronization and data buffering. All RF-critical components are integrated on a single chip minimizing the number of required external components to the antenna, crystal and decoupling capacitors. The bidirectional differential antenna pins, used for transmission and reception, eliminate the need for an external antenna switch. An internal 128 byte RAM buffers transmit and receive data. Two on chip low dropout (LDO) voltage regulators provide the internal analog and digital 1.8V supply.