| 摘要 |
PROBLEM TO BE SOLVED: To provide a current detecting circuit that has a simple circuit constitution, and can remarkably be reduced in the number of circuit elements. SOLUTION: This circuit has third and fourth transistors Q9, Q10 operated to bring the ratio of a collector current flowing in the first transistor Q7 based on an input terminal side potential in a detecting resistor RLS to a collector current flowing in the second transistor Q8 based on an output terminal side potential in the detecting resistor RLS into a prescribed ratio, the sixth transistor Q12 for making a collector current based on a collector current of the fifth transistor Q11 for supplying a collector current of the fourth transistor Q9 flow, and the seventh transistor Q13 for changing a current detection output by switching between ON and OFF when a collector current of the sixth transistor Q12 exceeds a prescribed value. A current flowing in the detecting resistor RLS is accurately detected thereby, and the circuit constitution is remarkably simplified thereby to be able to reduce the number of the circuit elements. COPYRIGHT: (C)2003,JPO
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