GENERAL DESCRIPTION
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).

FEATURES
RF bandwidth 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
Digital lock detect
Power-down mode
Pin compatible with the ADF4110/ADF4111/ADF4112/ADF4113, ADF4106, ADF4153
Programmable modulus on fractional-N synthesizer
Trade-off noise vs. spurious performance
Fast-lock mode with built-in timer
Loop filter design possible with ADIsimPLL™