| 摘要 |
PROBLEM TO BE SOLVED: To enable a normal operation even when an input voltage correspond ing to hysteresis width is inputted by controlling the order of the continuity of a switch by the output of the previous voltage comparison circuit in time- sharing operation when shifting from non-operation state to operation one. SOLUTION: The output potential of a reference voltage source 102 is inputted to the first input of a voltage comparator 101 as first reference potential. On voltage comparison operation, potential being obtained by dividing the first reference potential and the potential of an input signal IN with a resistor is connected to the second input of the voltage comparator 101. A switch control part 111 uses an external input signal EN for controlling voltage comparison operation and non-operation by timesharing as the input, and has a function for maintaining an output signal 110 of the voltage comparator 101 immediately before shifting from comparison operation to non-comparison one. Then, when shifting from the non-comparion operation to the comparisod operation, short- circuiting control signals 111a and 111b are outputted according to the retained signal, where the control signals short-circuit switches S1 and S2 successively.
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