| 摘要 |
PROBLEM TO BE SOLVED: To provide a comparator having hysteresis in which the number of elements is small and which is not affected by temperature. SOLUTION: When the input of an input terminal 1 goes up from voltage less than a threshold to a level equal to or more than voltage equal to or more than the threshold, a switch control circuit 5 controls a switch 7 to turn on from turned off. At this time, a collector current I2 of a transistor Q2 is caused to flow to a transistor Q1 and a resistor R2 through the switch 7 and does not affect a reference voltage Vref. When the input of the input terminal 1 goes down to a voltage lower than the threshold from voltage equal to or more than the threshold, the switch control circuit 5 controls the switch 7 to turn off from turned on. At this time, the collector current I2 of the transistor Q2 is caused to flow to the transistor Q1 and the resistor R2 through a resistor R3 to make voltageΔV determined with the current I2 and the resistance R3 the hysteresis.
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