Apparatus and method for acquisition and tracking bank cooperation in a digitally controlled oscillator

摘要

A novel apparatus for and method of acquisition and tracking bank cooperation in a digitally controlled oscillator (DCO) within an all digital phase locked loop (ADPLL). The acquisition bits of the acquisition bank are used as an extension of the modulation range. The PLL and TX tuning data are broken up (i.e. apportioned) into acquisition components and tracking components. This permits the use of two different capacitor banks (i.e. the tracking and acquisition banks) for modulation rather than just a single capacitor bank as in the prior art schemes. Incorporating the tracking and acquisition bit varactors, the cooperation scheme of the present invention permits the re-centering of the tracking bank to handle natural frequency drift of the DCO and the widening of the modulation range.