24.84 MHz Phase-frequency detector with charge pump

180TSMC_PFD_01 is a phase-frequency detector (PFD) forms a control signal for VCO tuning. PFD compares phases of a divided VCO signal and a divided reference oscillator signal and detects phase difference. Charge pump (CP) generates pulses for the loop filter. The structure consists of two types of PFD with CP: ECL and CMOS choosing by a bit PFD_TP. The lock detector monitors the current status of PLL by comparing the phase difference of VCO divided signal and reference oscillator signal with required value. LD_MP<1:0> and LD_ACR outputs set the lock monitoring period and the lock detector accuracy, respectively.