| 摘要 |
PROBLEM TO BE SOLVED: To realize a current mirror circuit capable of making the voltage of a current input terminal which is needed to be equal to or more than the conventional 2VBE (VBE is an inter-BE voltage of a transistor when current is caused by flow in an active region) for switching small almost to the VBE. SOLUTION: Switching can be conducted even though the base and the collector of a transistor Q1 are directly connected because the inter-BE voltage of the transistor Q1 constituting a current mirror can be immediately made not higher than 1VRE by making current from a current source I4 flow to a resistor R3 where an emitter current is caused to flow and making voltage that is thereby increased at both ends of the resistor R3 surpass a switching input voltage E0 when a transistor Q3 is turned on and the switching input voltage E0 becomes a prescribed voltage. Thus, it is possible to make the voltage of a current input terminal I lower by 1VBE than in the conventional practice when the current mirror circuit is turned on and also to optionally set an input voltage with which switching is completed.
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