Programmable sample rate analog to digital converter and method for use therewith
AssigneeSigmatel, Inc.
InventorMichael May
Life of this patent
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Abstract
A programmable sample rate ADC includes a delta sigma modulator for producing a digital signal, and a programmable decimation filter, that includes X stages of integration, a down-sampling stage for down-sampling by a factor of N, and Y stages of differentiation. The programmable sample rate ADC produces a digital output signal at a substantially constant frequency.
Claims12
1-31. (canceled)
A radio receiver front end for receiving a received radio signal having a plurality of channel signals, each, of the plurality of channel signals being modulated at one of a corresponding plurality of carrier frequencies, and for converting a selected one of the plurality of channel signals into a digital baseband signal, the radio receiver front end comprising:
- a channel selector, for producing a control signal that corresponds to a selected one of the plurality of channels;
- a local oscillator, operatively coupled to a reference oscillation, for producing a local oscillation signal at a local oscillation frequency, the local oscillation frequency based on the control signal;
- an analog to digital converter module, operatively coupled to a modulated signal, the modulated signal operably coupled to the receive radio signal, and a variable frequency clock signal that varies as a function of the local oscillation frequency for producing a digital signal.
A method for use in a radio receiver front end for receiving a received radio signal having a plurality of channel signals, each of the plurality of channel signals being modulated at one of a corresponding plurality of carrier frequencies, and for converting a selected one of the plurality of channel signals into a digital baseband signal, the radio receiver front end comprising:
- generating a local oscillation signal at a local oscillation frequency, the local oscillation frequency based on a selected one of the plurality of channels;
- analog to digital converting an intermediate frequency signal to a digital signal based on a variable frequency clock signal that varies as a function of the local oscillation frequency.
Dependencies are inferred from the claim text.