| 摘要 |
PURPOSE:To prevent a power supply ripple from appearing at an output by extracting only the power supply ripple and applying subtraction so as to cancel the power supply ripple at an input of an amplifier circuit. CONSTITUTION:The phase of an output o an in-phase amplifier 17 and that of a buffer transistor (TR)16 are opposite to each other when viewed from a stabilized power supply 4 as a reference, and the output of the in-phase amplifier 17 is (G-1).ER and the output of the TR16 is ER, where ER is the amplitude of the ripple of the stabilized power supply 4 and G is the gain of the amplifier 17. Thus the amplitude of respective power supply ripple appearing at an output V0 is (G-1).ER.R1/R3 and ER.R1/R2. Then the power supply ripple E2 of the stabilized power supply 4 does not appear at the output V0 by setting the relation of components as R2.(G-1)=R3.
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