Patent ID: 7253693
Filing Date: 2007-08-07
Classification: H03B,H03L

Abstract:
1. A method compensating for noise in a controllable oscillator, comprising: providing a first and a second capacitor respectively coupled to first and second tank circuit nodes; providing a switch between and selectively coupling the first and second capacitors according to a value of a control signal supplied to the switch, the switch having an associated first nonlinear capacitance that varies with a voltage at a third node coupled to the switch; and compensating for the first nonlinear capacitance with a second nonlinear capacitance coupled to the switch, the second nonlinear capacitance responsive to a change in the voltage at the third node to move a capacitance value of the second nonlinear capacitance in a direction opposite a direction of change of the first nonlinear capacitance in response to the change in the voltage.