It is a integer-N phase-locked loop frequency synthesizer (PLL) based on fully integrated 2GHz LC-VCO with low gain and fine phase noise performance. It work with reference frequency from 25 MHz XTAL oscillator or external signal source with frequency up to 500 MHz. Phase-frequency divider compare frequency can be equal or 2,3,4...63 times lower than reference. VCO frequency N-divider has programmable coefficient of division with step 1 in range 4 to 2047. Phase-frequency detector has built-in analog and digital lock detector circuits. Charge pump scheme with ADC and adjustable output current allow compensation VCO gain variation within band and keep loop gain constant. Integrated low-pass loop filter has adjustable values of resistance and capacitance for tune loop and get best phase-noise performance. All of output clocks have 0.5 duty cycle value using duty cycle recovery circuit.
The QF is designed using TSMC 65nm CRN65LP technology.