Patent Number: 6,515,533

Title: Multi-input comparator

Abstract: A multi-input comparator in accordance with the invention determines a minimum or maximum signal value in a given set of signal values. An illustrative embodiment of the multi-input comparator includes N inputs and generates an output corresponding to the maximum or minimum value in a set of signal values applied to the N inputs. The comparator includes a first comparison circuit, such as a sense amplifier, having inputs for receiving a subset of the N signal values, such as a pair of the inputs. The comparator also includes a first multiplexer having a select signal input coupled to an output of the first comparison circuit, and inputs coupled to the subset of the N signal values. The comparator further includes N-2 additional comparison circuits and N-2 additional multiplexers, with the N-2 additional multiplexers coupled to corresponding ones of the N-2 additional comparison circuits. The comparison circuits and multiplexers are arranged to select a particular one of the N signal values, e.g., the maximum or the minimum value. The additional comparison circuits and multiplexers may be arranged in, for example, a linear architecture or a logarithmic architecture. The comparator may be used in conjunction with a position determination circuit which indicates the position of the maximum or minimum value in the set of signal values, or produces a desired ordering of the signal values.

Inventors: Gabara; Thaddeus John (Murray Hill, NJ), Mujtaba; Syed Aon (Berkeley Heights, NJ)

Assignee: Agere Systems Inc.

International Classification: H03K 5/22 (20060101); H03K 5/24 (20060101); H03K 017/62 (); G01R 019/00 ()

Expiration Date: 02/04/2020