Multi-bit ΔΣ modulator having linear output
AssigneeHRL Laboratories, LLC
InventorsGopal Raghavan, Henrik T. Jensen
Life of this patent
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Abstract
An apparatus and method of improving linearity of a multi bit ΔΣ modulator in which the output of a multi-bit quantizer of a ΔΣ modulator is connected in a feedback loop to a converter where output is a higher frequency single bit data stream which is supplied to a 1-bit digital to analog converter whose output is fed back to the quantizer to provide linearity of the output of the ΔΣ modulator.
Claims14
A ΔΣ modulator comprising a multi bit quantizer having an input and an output, and a feedback loop connected from the output of the quantizer back to the input thereof, a 1 bit digital to analog converter in said feedback loop, and converter means connected between the output of the quantizer and an input of the 1-bit digital to analog converter for converting an m-bit output of the quantizer to a 1-bit output which is input to said 1-bit digital to analog converter, to provide substantial linearity of the output of the modulator.
A method of improving linearity of multi bit ΔΣ modulation comprising connecting the output of a multi-bit quantizer of a ΔΣ modulator in a feedback loop, converting said output to a higher frequency single bit data stream and driving a 1-bit digital to analog converter with said single bit data stream, the output of the 1-bit digital to analog converter being connected to the input of the quantizer whereby to provide linearity of the output of the ΔΣ modulator.
A ΔΣ modulator comprising:
- a multi bit quantizer operating at a clock frequency fclk, and having an input and an output;
- a feedback loop connected from the output of the quantizerback to the input thereof;
- a 1-bit digital to analog converter in said feedback loop;
- and
- a converter connected between the output of the quantizer and an input of the 1-bit digital to analog converter for converting a m-bit output of the quantizer to a 1-bit output at a frequency higher than the clock frequency, which is input to said 1-bit digital to analog converter to provide substantial linearity of the output of the modulator.
Dependencies are inferred from the claim text.