| 摘要 |
PROBLEM TO BE SOLVED: To enable the detection of an output current by a simple circuit without inserting a resistance for current detection into a circuit such as a regulator circuit through which a large current is passed from an output terminal. SOLUTION: A constant-current source 12 is provided between an input terminal 11 and an output terminal 13. The current detecting circuit of a regulator circuit 10 to control a current Ia which flows from the constant-current source 12 to the output terminal 13 by a current control circuit Q1 provided with a reference voltage Va is constituted of another constant-current source 14 connected to the input terminal 11, first current mirror circuits Q2 and Q3 with two inputs each connected to the current control circuit Q1 and the constant-current source 14 to make a current from the current control circuit Q1 and a current from the constant-current source 14 flow at a ratio of N:1, and a resistance Rm for monitoring currents connected in parallel to the first current mirror circuit Q3 on the side connected to the constant-current source 14. It is possible to convert a current Iout which flows through the output terminal 13 at both ends of the resistance Rm for monitoring currents into voltage and to detect it.
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