The transmitter’ s carrier frequency fc is determined by the frequency of the reference crystal fref. The integrated PLL synthesizer ensures that carrier frequencies, ranging from 425MHz to 445MHz, can be achieved. This is done by using a crystal with a reference frequency according to: fref = fc/N, where N = 16 is the PLL feedback divider ratio.
Features and Benefits
Fully integrated PLL-stabilized VCO Frequency range from 425 MHz to 445 MHz Single-ended RF output FSK through crystal pulling allows modulation from D C to 40 kbit/ s High FSK deviation possible for wideband data transmission Wide power supply range from 1.95 V to 5.5 V Operating temperature range -40°C to +125°C V ery low standby current On-chip low voltage detector High over-all frequency accuracy FSK deviation and center frequency independently adjustable Adjustable output power range from -16 dBm to +12 dBm Adjustable current consumption from 3.5 mA to 15.9 mA Conforms to EN 300 220 and similar standards