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US 2011/0254718 A1Published application
Integrator and delta-sigma modulator including the same
AssigneePanasonic Corporation
InventorsKazuo MATSUKAWA, Shiro DOSHO, Yosuke MITANI, Koji OBATA
Life of this patent
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Abstract
An integrator is provided which can reduce a disturbance in the current waveform of a current DA converter in order to improve the SNR of a ΔΣ modulator, for example. The integrator includes an operational amplifier, and feedback paths provided in parallel between the output terminal and inverting input terminal of the operational amplifier. In one of the feedback paths, an integrating capacitor and at least one resistor are connected in series. In the other feedback path, a second integrating capacitor whose capacitance value is smaller than that of the integrating capacitor is provided.
Claims10
An integrator comprising:
- an operational amplifier;
- a voltage input terminal connected via an input resistor to an inverting input terminal of the operational amplifier;
- and
- a first and a second feedback path connected together in parallel between an output terminal and the inverting input terminal of the operational amplifier,
- wherein
- in the first feedback path, a first integrating capacitor and at least one first resistor are connected together in series, and
- in the second feedback path, a second integrating capacitor having a smaller capacitance value than that of the first integrating capacitor is provided.
4 more elements
A ΔΣ modulator comprising:
- an integration circuit section configured to receive a signal and output an integrated signal;
- a quantizer configured to receive an output signal of the integration circuit section and output a quantized signal;
- a current DA converter configured to receive the quantized signal and output a current signal,
- wherein
- the integration circuit section includes
- an integrator including
- an operational amplifier,
- a signal input terminal connected via an input resistor to an inverting input terminal of the operational amplifier,
- a first feedback path including a first resistor and a first capacitor connected together in series between an output terminal and the inverting input terminal of the operational amplifier, and
- a second feedback path including a second capacitor connected between the output terminal and the inverting input terminal of the operational amplifier, and
- an output signal of the current DA converter is supplied to the inverting input terminal of the operational amplifier.
8 more elements
A ΔΣ modulator comprising:
- a first integrator;
- a second integrator;
- a quantizer configured to receive an output signal of the second integrator and output a quantized signal;
- and
- a current DA converter configured to receive the quantized signal and output a current signal,
- wherein
- the first integrator includes
- a first operational amplifier,
- a first signal input terminal connected via an input resistor to an inverting input terminal of the first operational amplifier,
- a first feedback path including a first resistor and a first capacitor connected together in series between an output terminal and the inverting input terminal of the first operational amplifier, and
- a second feedback path including a second capacitor connected between the output terminal and the inverting input terminal of the first operational amplifier,
- the first integrator integrates a signal supplied to the first signal input terminal and outputs the integrated signal,
- the second integrator includes
- a second operational amplifier,
- a second signal input terminal connected via an input resistor to an inverting input terminal of the second operational amplifier, and connected to an output terminal of the first integrator,
- a third feedback path including a second resistor and a third capacitor connected together in series between an output terminal and the inverting input terminal of the second operational amplifier, and
- a fourth feedback path including a fourth capacitor connected between the output terminal and the inverting input terminal of the second operational amplifier,
- the second integrator integrates a signal supplied to the second signal input terminal and outputs the integrated signal, and
- an output signal of the current DA converter is supplied to the inverting input terminal of the first operational amplifier.
16 more elements
Dependencies are inferred from the claim text.