Patent ID: 7170330
Filing Date: 2007-01-30
Classification: H03K

Abstract:
1. A hysteresis comparator circuit comprising: a comparator that outputs a H-level voltage when a voltage applied to its non-inverting input terminal is equal to or larger than a voltage applied to its inverting input terminal, and outputs a L-level voltage when the above condition is not satisfied; first and second resistors connected in series between a potential reference line and a first power line for supplying a first constant voltage being set based on an electric potential of the potential reference line in this order, with the first resistor connected to the first power line; a third resistor connected between an interconnection point of the first and second resistors and the non-inverting input terminal of the comparator; a first constant current source circuit for supplying a predetermined constant current to the interconnection point only while the output voltage of the comparator is the L-level; and a second constant current source circuit for absorbing a constant current equal to the constant current supplied by the first constant current source circuit from the non-inverting input terminal of the comparator only while the output voltage of the comparator is the L-level, wherein an input voltage that is set based on the electric potential of the potential reference line is applied to the inverting input terminal of the comparator.