Patent ID: 6940329

Claim:
A hysteresis circuit for a comparator, said comparator comprising an input stage including a first transistor and a second transistor, each having a gate terminal serving as one of two input terminals of said comparator to receive one of two input signals, said comparator further comprising a constant current source connected to supply a constant current to said input stage of said comparator, said hysteresis circuit comprising: a first resistor element coupled between a source terminal of said first transistor and said constant current source of said comparator; a second resistor element coupled between a source terminal of said second transistor and said constant current source of said comparator; a first current generating means for supplying a first current to said source terminal of said first transistor and deriving a fourth current out from said source terminal of said second transistor when an output signal from an output terminal of said comparator is a first logic value; and a second current generating means for supplying a third current to said source terminal of said second transistor and deriving a second current out from said source terminal of said first transistor when said output signal from said output terminal of said comparator is a second logic value.