Digital converter
OwnerPeter Graham Craveninventor
Life of this patent
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Abstract
A digital converter includes a consecutive edge modulator and a noise-shaping circuit. The noise-shaping circuit modifies the input to the consecutive edge modulator in dependence upon values corresponding to the output of the consecutive edge modulator. The noise-shaping circuits apply different respective non-linear functions to samples corresponding to the trailing-edge and leading-edge outputs respectively of the consecutive edge modulator. The noise-shaping circuit may act upon an output simulating the output of the consecutive edge modulator for a given input sample value. A look-up table may be used to simulate the consecutive edge modulator output
Claims26
A digital converter including a consecutive edge modulator (50'), and a noise-shaping circuit (30) arranged to modify the input to the consecutive edge modulator in dependence upon values corresponding to an output of the consecutive edge modulator, characterised in that the noise-shaping circuit (30) is arranged to apply different respective non-linear functions to samples at time instants corresponding to trailing-edge and leading-edge outputs respectively of the consecutive edge modulator.
A digital converter including a consecutive edge modulator (50), and a noise-shaping circuit (30) arranged to modify the input to the consecutive edge modulator in dependence upon values corresponding to an output of the consecutive edge modulator, characterised in that the noise-shaping applied to the input of the consecutive edge modulator is effective at an oversampling frequency equal to twice the switching frequency of the output of the consecutive edge modulator and in that the level of noise-reduction within the baseband effected by the noise-shaping circuit is substantially independent of the signal modulation level.
A method of operating a digital converter including a consecutive edge modulator, the method including applying noise-shaping to the input to the consecutive edge modulator, characterised by applying different respective non-linear functions to samples at time instants corresponding to trailing edge and leading edge outputs respectively of the consecutive edge modulator.
A method of operating a digital converter including a consecutive edge modulator, the method including applying noise-shaping to the input to the consecutive edge modulator, characterised in that the noise shaping is effective at an oversampling frequency equal to twice the switching frequency of the output of the consecutive edge modulator and in that the level of noise-reduction within the baseband effected by the noise-shaping circuit is substantially independent of the signal modulation level.
A digital converter including an input for a signal to be converted;
- means for generating a quantised signal from the said signal to be converted;
- a consecutive edge modulator connected to the said means for generating;
- and a noise shaping circuit connected in the input path to said consecutive edge modulator;
- wherein said noise shaping circuit includes means for applying different respective functions to input samples corresponding to trailing edge and leading edge outputs of said consecutive edge modulator.
Dependencies are inferred from the claim text.