Patent ID: 8275336

Claim:
An oscillator circuit having at least one output frequency, the output frequency changing as a capacitance in the oscillator circuit varies, the oscillator circuit comprising: a discretely switchable capacitance module configured to control an amount of the capacitance in the oscillator circuit, the discretely switchable capacitance module having a capacitor coupled between a first node and a second node; a switch, having a control node, coupled between the second node and a third node; and a DC-feed circuit, having a first end coupled to the second node and a second end configured to receive a first control signal or a second control signal, wherein the control node of the switch is tied to a predetermined bias voltage, and when the first control signal is applied to the second end of the DC feed circuit an AC signal of the oscillator circuit passes through the capacitor, and when the second control signal is applied to the second end of the DC feed circuit the AC signal of the oscillator circuit does not pass through the capacitor and the switch.