Patent ID: 6229350
Filing Date: 2001-05-08
Classification: H03K

Abstract:
A hysteretic comparator for comparing a sample voltage comprising:a reference voltage generator providing a voltage V.sub.REF ;a hysteresis voltage generator providing a voltage V.sub.HYST- and a voltage V.sub.HYST+ ;a first differential input stage generating a signal coupled to a summing node determined from a difference between the sample voltage and V.sub.REF ;a second differential input stage generating a signal coupled to the summing node determined from a positive difference between V.sub.HYST- and V.sub.HYST+ ;a third differential input stage generating a signal coupled to the summing node determined from a negative difference between V.sub.HYST- and V.sub.HYST+ ;a control device coupled to selectively enable the second and third differential input stages to select among a first mode and a second mode wherein the hysteresis voltage generator derives V.sub.HYST- and the voltage V.sub.HYST+ from V.sub.REF.