A/D (analog-to-digital) converter
AssigneeKabushiki Kaisha Toshiba
InventorHiroshi Tanimoto
Life of this patent
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Abstract
An A/D converter comprises a first stage integrator for receiving an input signal, a last stage integrator, a multibit A/D converter connected to the output terminal of the last stage integrator, an outer feedback loop connected between the output terminal of the multi-bit A/D converter and the input terminal of said first stage integrator and having a 1-bit D/A converter, an inner feedback loop connected between the output terminal of the multibit A/D converter and the input terminal of the last stage integrator and having a multibit D/A converter, and a digital signal processing circuit, connected to the output terminal of the A/D converter, for performing digital signal processing of an output from the A/D converter to eliminate quantization noise caused by the outer feedback loop.
Claims17
An A/D converter comprising:
- a plurality of stages of integrating means having first stage integrating means for receiving an input signal and last stage integrating means;
- at least one A/D converting means connected to an output terminal of said last stage integrating means;
- at least one outer feedback loop connected from an output terminal of said A/D converting means to at least said first stage integrating means and including first D/A converting means;
- a plurality of inner feedback loops including second D/A converting means connected between the output terminal of said A/D converting means and said plurality of stages of integrating means arranged after said first stage integrating means;
- and
- means, connected to the output terminal of said A/D converting means, for performing digital signal processing of an output from said A/D converting means to eliminate quantization noise caused by said outer feedback loop,
- wherein said second D/A converting means included in said inner feedback loop has a number of quantization levels larger than that of said first D/A converting means used in said outer feedback loop.
An A/D converter comprising:
- a plurality of stages of integrating means having first stage integrating means for receiving an input signal and last stage integrating means;
- a multibit A/D converter connected to an output terminal of said last integrating means;
- an outer feedback loop (FBL1) connected between an output terminal of said multibit A/D converter and an input terminal of said first stage integrating means and including a 1-bit D/A converter;
- an inner feedback loop (FBL0) including a multibit D/A converter connected between the output terminal of said multibit A/D converter and input terminals of said plurality of stage integrating means arranged after said first stage integrating means;
- and
- means, connected to the output terminal of said A/D converter, for performing digital signal processing of an output from said multibit A/D converter to eliminate quantization noise caused by said outer feedback loop.
Dependencies are inferred from the claim text.