Differential input circuit for digital signal processing system
AssigneeMicronas GmbH
InventorFranz Kuttner
Life of this patent
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Abstract
The invention relates to an evaluation device (4) connected to the output of an A/D converter (3) for comparing the direct component of a digitally converted input signal having a threshold value and at least one power source (13, 14, 17, 18) that may be connected to the differential input (1) by the evaluation device (4) in such a way that the differential input (1) can be loaded or unloaded with a current to increase or reduce the direct component in the direction of the threshold value.
Claims17
A differential input circuit for a digital signal processing system, said differential input circuit comprising:
- a low pass filter that receives a compensated differential input signal, and provides a filtered differential input signal;
- an analog-to-digital converter that receives said filtered differential input signal, and provides a digitized signal indicative of the difference between inverting and non-inverting signal components of said filtered differential input signal;
- an evaluation unit that receives said digitized signal, and compares said digitized signal against a threshold value, and provides an output signal indicative of the difference between said digitized signal and said predetermined threshold value;
- and
- means, responsive to said output signal and an analog differential input signal having analog inverting and non-inverting signal components, for adjusting the voltage difference between said analog inverting and non-inverting signal components in response to said output signal using a plurality of switched current sources, to provide said compensated differential input signal.
A differential input circuit for a digital signal processing system, comprising:
- means, for receiving and low pass filtering a differential input signal, and for providing a filtered analog differential input signal indicative thereof having inverting and non-inverting signal components;
- means for digitizing said filtered analog differential input signal, and for providing a digital input signal indicative of the difference between said inverting and non-inverting signal components;
- and
- means, responsive to said digital input signal, for comparing said digital input signal against a threshold value, and for providing at least one command signal to said means for receiving to regulate the difference between said inverting and non-inverting signal components such that said digital input signal is driven towards said threshold value,
- wherein said means for receiving comprises a plurality of switched current sources responsive to said at least one command signal, to control the voltage difference between said inverting and non-inverting signal components.
A differential input circuit, comprising:
- a plurality of switched current sources responsive to a differential input signal and at least one command signal, to control the voltage difference between inverting and non-inverting signal components and provide a compensated differential input signal;
- means, for receiving and low pass filtering said compensated differential input signal, and for providing a filtered analog differential input signal indicative thereof having filtered inverting and non-inverting signal components;
- means for digitizing said filtered analog differential input signal, and for providing a digital input signal indicative of the difference between said filtered inverting and non-inverting signal components;
- and
- means, responsive to said digital input signal, for comparing said digital input signal against a threshold value, and for providing said at least one command signal to regulate the difference between said inverting and non-inverting signal components such that said digital input signal is driven towards said threshold value.
Dependencies are inferred from the claim text.