Digital phase-locked loop device with automatic frequency range selection

摘要

A digital phase-locked loop (PLL) device includes a digital loop filter (106) which is provided with both a VCO-loop output and a DCO-loop output. The VCO-loop output is connected to an analog input of a multiband voltage-controlled oscillator (VCO) module (100) for allowing usual operation of the PLL with a direct voltage acting as feedback parameter. The DCO-loop output is connected to a digital control input of the multiband VCO module for allowing automatic frequency range selection. A code value which is produced by the digital loop filter acts as feedback parameter during the frequency range selection. Rapid and precise range selection can thus be performed.