The ADF4169 synthesizer features a programmable reference divider, a low-noise digital phase frequency detector (PFD), and a precision charge pump. A ∑-Δ-based fractional interpolator enables programmable fractional-N division. The synthesizer's INT and FRAC registers define an overall N divider as N = INT + (FRAC/225). A simple 3-wire interface controls all on-chip registers.
Designers can use the ADF4169 synthesizer to integrate frequency shift keying (FSK) and phase-shift keying (PSK) modulation. In addition, frequency sweep modes are available for various waveforms in the frequency domain. Designers can set up sweeps to run automatically or have an external pulse trigger each step manually.
The design also includes cycle slip reduction circuitry to allow faster lock times without modifications to the loop filter.
The ADF4169 operates with a 2.7V to 3.45V analog power supply and a 1.8V to 2.0V digital power supply. When not in use, the ADF4169 synthesizer can be powered down.