nRF902 is a single-chip transmitter for the 868 MHz ISM band, designed to comply
with the ETSI specification I-ETS 300 220. Using nRF902 both FSK and ASK
modulation is possible. The transmitter consists of a fully integrated frequency
synthesiser, a power amplifier, a crystal oscillator and a modulator. Few external
components are required: a 13.567 MHz crystal, two resistors and some decoupling
capacitors. Due to the use of the crystal-oscillator stabilised frequency synthesiser,
frequency drift is much lower than in comparable SAW-resonator based solutions.
Output power is easily programmable by use of an external resistor. Current
consumption is very low, only 9 mA at an output power of –10dBm. Built-in Clock
and Power Down modes makes power saving and duty-cycling easily realisable.