| 摘要 |
PROBLEM TO BE SOLVED: To provide a simple method consuming a small amount of power for controlling a threshold. SOLUTION: A comparator 30 includes transistors(TRs), each source and each drain of which are connected in series between a line of a power supply voltage VDD and an output node and each gate of which is connected to an input node. The comparator 30 also includes a plurality of TR pairs that are connected in series between the output node and ground in a way that the source of a 1st TR and the drain of a 2nd TR of each TR pair are connected. The gate of the 1st TR of each TR pair is connected to the input node and the gate of the 2nd TR of each TR pair receives a specific control signal. The threshold voltage of the comparator can be selected by supplying one or a plurality of control signals to one or a plurality of concerned gates of the 2nd TR of each TR pair respectively.
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