The SY89421V is a digital Phase Locked Loop based on Micrel-Synergy's differential PLL technology. It is capable of operating in the 30MHz to 560MHz reference input frequency range, and up to 2000MHz with the HFIN input and an external VCO. Use of a phase-frequency detector results in excellent PLL locking and tracking characteristics. Error correction voltages are generated by the detector if either phase or frequency deviations occur. The VCO has a frequency range covering more than a 2:1 ratio from 480MHz to 1120MHz.