Delta sigma modulator
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsFumihito INUKAI, Hitoshi Kobayashi
Life of this patent
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Abstract
In a delta sigma modulator including first and second integration circuits connected in cascade, each as a component thereof, first and second power source terminals for supplying first and second different power source voltages to the first and second integration circuits are provided. The first power source voltage is supplied to the former-stage first integration circuit having a SNR which is largely affected by the magnitude of the power source voltage. The second power source voltage lower than the first power source voltage is supplied to the latter-stage second integration circuit having a SNR which is not largely affected by the magnitude of the power source voltage.
Claims28
A delta sigma modulator including an integration circuit, and a quantizer for quantizing an output of the integration circuit, an output of the quantizer being feedbacked to the input side of the integration circuit, the delta sigma modulator comprising:
- a first power source terminal for supplying a first operation power source voltage to the integration circuit;
- and
- a second power source terminal for supplying a second operation power source voltage lower than the first operation power source voltage to the quantizer.
A delta sigma modulator including a first integration circuit, a second integration circuit for integrating an output of the first integration circuit, and a quantizer for quantizing an output of the second integration circuit, an output of the quantizer being feedbacked to the input side of the first integration circuit, the delta sigma modulator comprising:
- a first power source terminal for supplying a first operation power source voltage to the first integration circuit;
- and
- a second power source terminal for supplying a second operation power source voltage lower than the first operation power source voltage to the second integration circuit.
A delta sigma modulator comprising:
- a first-stage delta sigma modulation type quantization loop including a first integration circuit, and a first quantizer for quantizing an output of the first integration circuit, an output of the first quantizer being feedbacked to the input side of the first integration circuit;
- a subsequent-stage delta sigma modulation type quantization loop connected in cascade to the first-stage delta sigma modulation type quantization loop, and including a second integration circuit, and a second quantizer for quantizing an output of the second integration circuit, an output of the second quantizer being feedbacked to the input side of the second integration circuit;
- and
- a noise removal circuit receiving an output of the first-stage delta sigma modulation type quantization loop, and an output of the subsequent-stage delta sigma modulation type quantization loop to remove noise included in the output of the first-stage delta sigma modulation type quantization loop,
- the delta sigma modulator further comprising:
- a first power source terminal for supplying a first operation power source voltage to the first integration circuit;
- and
- a second power source terminal for supplying a second operation power source voltage lower than the first operation power source voltage to the second integration circuit.
Dependencies are inferred from the claim text.