PHASE MARGIN GAIN MARGIN MEASURING CIRCUIT

摘要

PROBLEM TO BE SOLVED: To allow measurements of a phase margin and a gain margin of a measurement target circuit without cutting connection between an output terminal of an operational amplifier and a feedback circuit and inserting a measurement device between the output terminal and the feedback circuit, even if a measurement resistor is not inserted in a part of a closed loop.;SOLUTION: The measurement device includes: a phase gain calculating part 22 calculating a phase and a gain of a measurement target circuit 1; a frequency control part 24 making the frequency of a signal VS output from a signal source 21 variable; and a margin specification part 25 specifying a phase margin and a gain margin of the measurement target circuit 1 based on phases and gains of the measurement target circuit 1 at various different frequencies.;SELECTED DRAWING: Figure 1;COPYRIGHT: (C)2017,JPO&INPIT