The ADF4154 is a fractional-N frequency synthesizer that implements local oscillators in the up conversion and down conversion sections of wireless receivers and transmitters. It consists of a low noise digital phase frequency detector (PFD), a precision charge pump, and a programmable reference divider. There is a Σ-Δ based fractional interpolator to allow programmable fractional-N division. The INT, FRAC, and MOD registers define an overall N divider (N = (INT + (FRAC/MOD))). In addition, the 4-bit reference counter (R counter) allows selectable REFIN frequencies at the PFD input. A complete phase-locked loop (PLL) can be implemented if the synthesizer is used with an external loop filter and a voltage controlled oscillator (VCO). A key feature of the ADF4154 is the fast-lock mode with a builtin timer. The user can program a predetermined count-down time value so that the PLL will remain in wide bandwidth mode, instead of having to control this time externally. Control of all on-chip registers is via a simple 3-wire interface. The device operates with a power supply ranging from 2.7 V to 3.3 V, and can be powered down when not in use. * RF bandwidth 500 MHz to 4 GHz * 2.7 V to 3.3 V power supply * Separate VP allows extended tuning voltage * Programmable dual-modulus prescaler 4/5, 8/9 * Programmable charge pump currents * 3-wire serial interface * Analog and digital lock detect * Power-down mode * Pin compatible with the ADF4110/ADF4111/ADF4112/ADF4113/ADF4106 and ADF4153 * Programmable modulus on fractional-N synthesizer * Trade-off noise versus spurious performance * Fast-lock mode with built-in timer https://elecena.pl/product/192459/fractional-n-frequency-synthesizer 2007-02-22 https://elecena.pl/product/192459/fractional-n-frequency-synthesizer 2018-03-29 https://elecena.pl/product/192459/fractional-n-frequency-synthesizer 2025-01-19