Patent ID: 7268604
Filing Date: 2007-09-11
Classification: H03K

Abstract:
1. A comparator comprising: a differential amplifier configured to amplify a difference signal corresponding to a difference between input signals of the differential amplifier; and a hysteresis circuit configured to set up a first transition threshold voltage and a second transition threshold voltage where the second transition threshold voltage is different from the first transition threshold voltage, and configured to generate a hysteresis output signal that makes a transition at the first transition threshold voltage when the difference signal changes in a first direction, and makes a transition at the second transition threshold voltage when the difference signal changes in a second direction, the hysteresis circuit including a Schmitt trigger circuit including: wherein the hysteresis-threshold setting unit adjusts a turn-on voltage of the pull-up driver or a turn-on voltage of the pull-down driver in response to a voltage level of the output terminal of the hysteresis circuit.