Circuit for comparing a three inputs

Abstract

A comparator circuit. A comparator circuit may include a differential amplifying unit to amplify a difference between a voltage at a first node and a voltage at a second node and / or output a resultant voltage, and / or a current source to supply a first bias current to a first node and / or supply a second bias current to a second node. A comparator may include a first bias switch to bias a current flowing from a first node to a ground voltage source, a second bias switch to bias a part of a current flowing from a second node to a ground voltage source, a third bias switch to bias a remaining part of a current flowing from a second node to a ground voltage source, and / or a bias converting unit to supply a third bias current to a second node.

Description

[0001] This application claims the benefit of Korean Patent Application No. 10-2008-0137259 filed on December 30, 2008, the entire contents of which are hereby incorporated by reference. technical field [0002] The present invention relates to a comparator circuit, and more particularly, to a comparator circuit for comparing three inputs. Background technique [0003] High-performance integrated circuits (ICs) use at least one comparator internally for precise control or various other functions. This comparator typically has two inputs. In order to realize more complex functions, a 3-input comparator is also widely used. [0004] figure 1 An associated comparator circuit 100 for comparing three inputs is shown. refer to figure 1 The 3-input comparator circuit 100 compares the voltage V1 of the first signal with the lower one of the voltage V2 of the second signal and the voltage V3 of the third signal, and outputs a comparison result. In this case, it is assumed that t...

AI Technical Summary

Problems solved by technology

However, when the difference between the third signal voltage V3 and the second signal voltage V2 is small, both the second and third transistors Q2 and Q3 may be turned on

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