MMWave 80GHz Analog FracN PLL with VCO frequency range 19.00-20.25 GHz, Including Integrated PFD, CP, LPF, VCO ...

Excluding the block marked Δ Σ (Delta-Sigma) Modulator, this PLL is same as a conventional PLL. A Phase-Frequency Detector (PFD, including a charge pump) compares a divided version of the VCO clock ...

and the PLL outputs a square wave that’s synced to the input, but at a higher frequency. It works by having a voltage-controlled oscillator (VCO) inside, and driving the VCO with a voltage ...