Multi-band voltage controlled oscillator controlling module, phase locked loop utilizing which and related method thereof
OwnerMei-Show Chen, Wei-Che Chung +1inventors
InventorsMei-Show Chen, Wei-Che Chung, Yan-Hua Peng
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Abstract
A multi-band VCO module includes a multi-band VCO and a controlling module. The multi-band VCO is for selecting a specific band from a plurality of bands according to a band selecting signal, and for outputting an oscillating signal according to a predetermined voltage and the specific band. The controlling module, coupled to the multi-band VCO, is for setting the band selecting signal according to a reference frequency of the reference signal and an oscillating frequency of the oscillating signal. A related method and a PLL circuit utilizing the multi-band VCO module are also disclosed.
Claims20
A multi-band voltage-controlled oscillator (VCO) module, comprising:
- a multi-band VCO, for selecting a specific band from a plurality of bands according to a band selecting signal, and for outputting an oscillating signal according to a predetermined voltage and the specific band;
- and
- a controlling module, coupled to the multi-band VCO, for setting the band selecting signal according to a reference frequency of a reference signal and an oscillating frequency of the oscillating signal.
A phase locked loop, comprising:
- a phase detector, for generating a phase detecting signal according to a reference frequency of a reference signal and an oscillating frequency of an oscillating signal;
- a charge pump, coupled to the phase detector, for generating a control current according to the phase detecting signal;
- a low-pass filter, coupled to the charge pump, for generating a filtered control voltage according to the control current;
- a switch module, coupled to the low-pass filter and a predetermined reference voltage, for outputting the filtered control voltage in a first mode and for outputting the predetermined reference voltage in a second mode;
- a multi-band VCO, coupled to the switch module, for selecting a specific band from a plurality of bands according to a band selecting signal, and for outputting an oscillating signal according to an output voltage of the switch module and the specific band;
- and
- a controlling module, coupled to the reference signal and the multi-band VCO, for setting the band selecting signal in the second mode according to the reference frequency and the oscillating frequency.
A method for controlling a multi-band voltage-controlled oscillator (VCO), wherein the multi-band VCO can support a plurality of bands, and an oscillating band of the multi-band VCO can approach a frequency corresponding to a target value by utilizing the method, the method comprises:
- dividing the plurality of bands into groups of a plurality of layers, and each group of each layer comprises at least a band;
- respectively searching a band most closely approaching the target value from the groups of all the layers according to the target value;
- selecting the oscillating band of the multi-band VCO from the searched bands.
Dependencies are inferred from the claim text.