METHOD AND APPATATUS FOR DIGITAL-CONTROLLED OSCILLATING USING WIDE BAND ACTIVE INDUCTOR WITH 3-STEP COARSE TUNING

摘要

PURPOSE: A method and an apparatus for digital-controlled oscillation using wide band active inductors with a 3-step coarse tuning manner are provided to have wide band tuning domain using a 3-step coarse tuning manner. CONSTITUTION: A digital-controlled oscillator core(310) comprises a cap bank, an active inductor, a manual inductor, and a negative GM circuit. A coarse tuning digital controller(320) controls 3-step coarse tuning operation of a digital-controlled oscillator(300). The DCO_OUT and the DCO_OUTB outputted in the digital-controlled oscillator core are dispensed through a 4(or 8)-divider(340). The outputted SDM_CLK is inputted to a sigma-DELTA modulator(330).