Patent ID: 7348861
Filing Date: 2008-03-25
Classification: H03B,H03L

Abstract:
1. A frequency generation circuit comprising: a control module adaptive to generate a control signal; and an oscillator circuit responsive to said control signal and adaptive to generate an output signal having a desired frequency, the oscillator circuit having a start-up time defined by the time required to reach the desired frequency and including, wherein with detection of a change of oscillation condition, the start-up time of the oscillator is changed by adjusting the capacitance ratio based on the capacitance of the first and second capacitors to achieve fast start-up time and to thereafter gradually program the first capacitor value to achieve an accurate and desired frequency associated with the output signal while the drivability of the amplifier is altered to reduce power consumption by the oscillation circuit through the control signal, further wherein a lower accuracy crystal resonator is employed to save system cost while accurate frequency control is achieved.