Patent ID: 8698565
Filing Date: 2014-04-15
Classification: H03J,H03L

Abstract:
1. A method for selecting an active voltage-controlled oscillator from two or more voltage-controlled oscillators comprising: establishing a capacitance range, which may include a minimum capacitance and a maximum capacitance, for at least one of a first voltage-controlled oscillator and a second voltage controlled oscillator and recording either a minimum capacitor control value, a maximum capacitor control value, or both for each capacitance range; determining an overlap region between the first voltage-controlled oscillator and the second voltage controlled oscillator, the overlap defined by overlap capacitor control values corresponding to overlapping frequency range between two voltage controlled oscillators; receiving a request for a signal at a requested frequency; determining if the requested frequency is in the overlap region; if the requested frequency is not in the overlap region, selecting whether to generate the signal at the requested frequency with the first voltage controlled oscillator or the second voltage controlled oscillator and generating the signal at the requested frequency with a selected voltage controlled oscillator; if the requested frequency is in the overlap region, executing a digital frequency centering (DFC) routine, for either the first voltage controlled oscillator or the second voltage controlled oscillator, which generates DFC routine capacitor control values; determining if the DFC routine capacitor control values are within an predetermined accepted range for the voltage controlled oscillator on which the DFC routine executed; if the DFC routine capacitor control values are within a predetermined accepted range for the voltage controlled oscillator on which the DFC routine executed, then selecting the voltage controlled oscillator on which the DFC routine executed to generate the signal at the requested frequency; and if the DFC routine capacitor control values are not within the predetermined accepted range for the voltage controlled oscillator on which the DFC routine executed, then selecting another voltage controlled oscillator to generate the signal at the requested frequency.