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US 7,482,885 B2Granted
Method of frequency synthesis for fast switching
AssigneeOrca Systems, Inc.
InventorKartik M. Sridharan
Life of this patent
Estimating the term…
Abstract
A digital frequency synthesizer can be implemented with single source design, a multiplexer design, a fractional divider design, or a frequency multiplier and frequency divider design. Implementations can utilize a controller dithering circuit or a delta-sigma modulator. The frequency synthesizer can be implemented in a CMOS structure and can utilize a clean up phase locked loop (PLL).
Claims25
A digital frequency synthesizer, comprising:
- at least one source for providing plurality of digital frequency signals, the digital frequency signals being provided at distinct frequencies;
- a plurality of switches coupled to receive the digital frequency signals;
- and
- a control circuit coupled to the switches, the control circuit controlling the switches to select the digital frequency signals and provide an output signal having an average frequency at a first frequency, the average frequency being within a range of the distinct frequencies, wherein the control circuit includes a clock input for receiving a clock signal, wherein the clock signal is the output signal or is derived from the output signal.
1 more element
A digital frequency synthesizer, comprising:
- at least one source for providing plurality of digital frequency signals, the digital frequency signals being provided at distinct frequencies;
- a plurality of switches coupled to receive the digital frequency signals;
- and
- a control circuit coupled to the switches, the control circuit controlling the switches to select the digital frequency signals and provide an output signal having an average frequency at a first frequency, the average frequency being within a range of the distinct frequencies, wherein the control circuit includes a dithering circuit or a delta sigma modulator.
1 more element
A digital frequency synthesizer, comprising:
- a frequency source for providing a first signal at a first frequency;
- a frequency multiplier for receiving the first signal and providing a second signal at a second frequency, the second frequency being a fixed integer multiple of the first frequency;
- a variable frequency divider for receiving the second signal and providing a third signal having an average third frequency, the average third frequency being less than the second frequency;
- a dithering circuit, wherein the divider is controlled by the dithering circuit so that the third frequency is an average of a dithering sequence from the dithering circuit.
1 more element
A digital frequency synthesizer, comprising:
- a plurality of digital frequency signal sources for providing plurality of digital frequency signals, the digital frequency signals being provided at distinct frequencies;
- a plurality of switches coupled to receive the digital frequency signals;
- and
- a control circuit coupled to the switches, the control circuit controlling the switches to select the digital frequency signals and provide an output signal having an average frequency at a first frequency, the average frequency being within a range of the distinct frequencies, wherein the control circuit includes a clock input for receiving a clock signal, wherein the clock signal is the output signal or is derived from the output signal.
1 more element
Dependencies are inferred from the claim text.