| 摘要 |
PURPOSE:To enable detection of current flowing in a load circuit at an optional rate when a transistor for outputting current that makes current flow in the load circuit is in the state of saturation by providing a transistor for outputting current and a differential circuit and a feedback circuit. CONSTITUTION:Driving currents I4, I5 are outputted from driving transistors (TR) Q4, Q5, and TRQ7 and TRQ6 for current output are driven in the state of saturation. Consequently, the TRQ7 becomes to apply a load current I0 to a load circuit RL. The TRQ6 outputs a collector current I6 and becomes to apply collector currents I13, I15 equal to a collector current I6 to TRQ13, Q15 by a current miller circuit consisting of a diode D5 and TRQ14, Q15. Collector potential VCE7, and VCE6, of TRQ7 and Q6 at this time is detected by a differential amplifier circuit 13. Above-mentioned collector potential VCE7 and VCE6 are controlled to become always equal by a feedback circuit consisting of the circuit 13, TRQ9, Q10 and D4. As I15 is equal to I6 at this time, a detection current of an optional ratio 1/N can be taken out.
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