2 GHz PLL synthesizer for RF LO generation
The ADF4208BRUZ is a single-channel PLL frequency synthesizer from Analog Devices, designed for RF local-oscillator generation up to 2 GHz. The 2 GHz max frequency covers UHF, ISM bands, and cellular basestation LO chains — the synthesizer's phase-noise floor and charge-pump linearity determine the close-in phase noise of the VCO it locks. Input accepts CMOS or TTL reference signals; output is a single-ended clock. The 3:1 input-to-output ratio allows multiplexing three reference sources into one PLL path — handy for redundant reference switching in a radio card.
The wide range also helps when the PLL shares a supply with a noisy digital rail; a little headroom lets an RC filter clean the feed before it hits the charge pump.
ROHS3 compliant.
Differential input, single-ended output
The reference input accepts differential signals (Yes/No for Input:Output) — useful when the reference is a differential OCXO or a balun-coupled sine source. The output is single-ended, so the PLL drives a standard CMOS clock buffer or a VCO tuning port directly.