Broadband sigma-delta modulator
AssigneeSiemens Aktiengesellschaft
InventorBjörn Jelonnek
Life of this patent
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Abstract
A sigma-delta modulator converting digital input signals x(k) includes a first feedback loop of a spectrally formed output signal y(k) of the sigma-delta modulator and a second feedback loop of a spectrally formed differential signal e(k), obtained from an intermediate signal u(k) and the output signal y(k). The intermediate signal u(k) constitutes the differential signal of the input signal x(k) and the total signal r(k) of the first and second feedback loops. A quantizer determines the output signal y(k) based on the intermediate signal u(k), whereby k is the discrete independent time variable. The sigma-delta converter generates a skew between the output signal y(k) and the input signal x(k).
Claims14
A sigma-delta modulator for converting digital input signals, comprising:
- at least one stage having
- a first feedback loop of a spectrally formed output signal of the sigma-delta modulator, dependent on a discrete independent time variable;
- a second feedback loop of a spectrally formed output differential signal obtained from the output signal and an intermediate signal formed by an input differential signal of an input signal and the total signal of the first and second feedback loops;
- a quantizer determining the output signal based on the intermediate signal;
- and
- skew means for generating a skew between the output and input signals, including at least one delay element creating a skew between clock cycles dependent on the discrete independent time variable, each clock cycle being a difference between two succeeding values of the discrete independent time variable.
Dependencies are inferred from the claim text.