| 摘要 |
PROBLEM TO BE SOLVED: To provide a current output circuit capable of simultaneously reducing the noise of an output current for a low current and obtaining an output current for a high current. SOLUTION: A current output circuit for a low current A and a current output circuit for a high current B are provided by sharing an output terminal OUT1. The current output circuit for a low current A comprises, such that one end part of an input resistance R11 is connected to one input end of an amplifier AMP1 which generates a constant current by using a virtual short circuiting, together with an input terminal IN1, and one end part of a load resistance R12 is connected to the other input end of the amplifier. The differential output of the amplifier is input into respective emitters of a pair of NPN transistors Q12, Q13. A current mirror circuit (PNP transistors Q14, Q15, Q16, and a current source I1) is connected to a collector thereof. The output is input into the base of a transistor Q11, serially connected to the load resistance R12 and is output from the collector. COPYRIGHT: (C)2008,JPO&INPIT
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