Parallel oversampling algorithmic A/D converter and method of using the same
AssigneeToyota Jidosha Kabushiki Kaisha
InventorHikaru Watanabe
Life of this patent
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Abstract
Each of plural sigma-delta modulators having a sampling capacitor, an integrator, and a quantizer are connected to each other in parallel. Each of the sigma-delta modulators conducts parallel oversampling in which an analog input signal is sampled by a sampling capacitor, and the sampling result is quantized by the integrator and the quantizer. Then, the quantized values of the sigma-delta modulators are added to obtain MSBs, the residue values of the integrators after quantizing in the respective sigma-delta modulators are added, and the addition result of the residue values is converted analog-to-digital to obtain LSBs.
Claims30
An A/D converter, comprising:
- a plurality of sigma-delta modulators which are connected to each other in parallel, and each of which has an integrator, and a quantizer;
- and
- a control unit that controls the plurality of sigma-delta modulators;
- wherein the control unit comprises:
- a parallel oversampling control unit that makes each of the sigma-delta modulators conduct sampling of an analog input signal and quantize a sampling result by the integrator and the quantizer;
- an MSBs calculating unit that adds quantized values in the respective sigma-delta modulators to obtain the MSBs;
- a residue adding unit that adds residue values of the integrators after quantization in the respective sigma-delta modulators;
- and
- an LSBs calculating unit that converts the addition result of the residue adding unit into a digital value to obtain LSBs.
An A/D conversion method using a plurality of sigma-delta modulators which are connected to each other in parallel, and each of which has a sampling capacitor, an integrator, and a quantizer, the method comprising:
- a parallel oversampling process of making each of the sigma-delta modulators conduct sampling of an analog input signal by the sampling capacitor and quantize a sampling result by the integrator and the quantizer;
- an MSBs calculating process to obtain MSBs by adding quantized values in the parallel oversampling process in the respective sigma-delta modulators;
- a residue adding process of adding residue values of the integrators in the respective sigma-delta modulators after the parallel oversampling process;
- and
- an LSBs calculating process of digitally converting the addition result of the residual adding process to obtain LSBs.
Dependencies are inferred from the claim text.