Multi-input comparator
AssigneeLucent Technologies Inc.
InventorThaddeus John Gabara
Life of this patent
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Abstract
A multi-input comparator determines a minimum or maximum signal value in a given set of signal values. In an illustrative embodiment, a multi-input comparator includes a number of interconnected inversion circuits, with each of the inversion circuits having an input node associated therewith. The input node of each of the inversion circuits is coupled to an output of at least one of the other inversion circuits. As a result, after activation of the inversion circuits, the voltages at the input nodes are indicative of the relative magnitude of the signal values previously applied thereto. The inversion circuits may be constructed using, for example, single-inverter or multiple-inverter building blocks. Additional inputs can be provided by replicating the corresponding single-inverter or multiple-inverter blocks.
Claims22
A comparator circuit having at least three inputs, the comparator circuit comprising:
- a first inversion circuit associated with a first input node of the comparator circuit;
- a second inversion circuit associated with a second input node of the comparator circuit;
- and
- at least one additional inversion circuit associated with an additional input node of the comparator circuit, wherein at least one of the first and second input nodes is coupled to an output of the at least one additional inversion circuit, and the additional input node associated with the at least one additional inversion circuit is coupled to an output of at least one of the first and second inversion circuits, and further wherein the comparator circuit is operative to generate a decision output signal indicative of a difference in input signal values associated with the first, second and additional input nodes ofthe comparator circuit.
A method of comparing at least three input signal values, comprising:
- applying the input signal values to a first input node of a comparator circuit, a second input node of the comparator circuit and at least one additional input node of the comparator circuit, wherein each of the input nodes is associated with a corresponding inversion circuit, at least one of the first and second input nodes is coupled to an output of the at least one additional inversion circuit, and the input node associated with the at least one additional inversion circuit is coupled to an output of at least one of the first and second inversion circuits;
- and
- generating a decision output signal indicative of a difference in input signal values associated with the first, second and at least one additional input nodes of the comparator circuit.
A comparator circuit comprising:
- at least three input nodes;
- and
- a plurality of interconnected inversion circuits, each having a particular one of the input nodes associated therewith, wherein at least one of the input nodes associated with a given one of the inversion circuits is coupled to an output of another one of the inversion circuits, and wherein the input node associated with the other inversion circuit is coupled to the input node of the given inversion circuit, and further wherein the comparator circuit is operative to generate a decision output signal indicative of a difference in input signal values associated with the at least three input nodes of the comparator circuit.
Dependencies are inferred from the claim text.