Patent ID: 6559730
Filing Date: 2003-05-06
Classification: H03B,H03J

Abstract:
An oscillator, having an adjustable frequency and a period of oscillation, comprising:a crystal resonator having first and second electrodes; a gain stage having first and second terminals connected to the first and second electrodes, respectively; a first bank of capacitors for providing a capacitive load to the crystal resonator at the first terminal; a second bank of capacitors for providing a capacitive load to the crystal resonator at the second terminal; each bank of capacitors having at least two capacitors connected in parallel connected to a reference voltage source and at least one switch operably connected to one of the at least two capacitors for selectively increasing and decreasing the capacitive load; a first dynamic switch interconnected between the first terminal and the first bank of capacitors, the first dynamic switch having a control input for receiving a static control voltage, the first dynamic switch being responsive to a voltage difference between the static control voltage and a voltage at the first terminal; and a second dynamic switch interconnected between the second terminal and the second bank of capacitors, the second dynamic switch having a control input for receiving a second static control voltage, the second dynamic switch being responsive to a voltage difference between the second static control voltage of the second dynamic switch and a voltage at the second terminal.