| 摘要 |
PROBLEM TO BE SOLVED: To provide a comparator circuit which has two functions of a constant current type hysteresis comparator and a voltage type hysteresis comparator and is capable of reducing a circuit scale. SOLUTION: The comparator circuit includes: a constant current source 12 capable of supplying a constant current; a comparator 11 for comparing signals supplied from input terminals IN1 and IN2; a resistor R1 whose one end is grounded; a resistor R2 whose one end is connected to the other end of the resistor R1, the constant current source 12 and the input terminal IN2; a switch S1 capable of applying a power supply voltage VDD to the other end of the resistor R2; a resistor R3 whose one end is connected to the constant current source 12 and other end is connected to an output driver 13; a switch S2 for switching whether or not to ground the other end of the resistor R3 on the basis of the output of the comparator 11; and a control part 10 for controlling ON/OFF of the switch S1 and the constant current source 12, turning the switch S1 OFF when turning the constant current source 12 ON and turning the constant current source 12 OFF when turning the switch S1 ON. COPYRIGHT: (C)2009,JPO&INPIT
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