| 摘要 |
PURPOSE:To measure accurately a differentiation gain DG by generating a test signal where a high frequency sinusoidal wave signal is superimposed on a low frequency step wave or sawtooth wave, applying it to an A/D converter (ADC), generating a sampling signal of four times frequency, extracting a component of the same frequency as that of a sinusoidal wave signal from the output of the ADC and adding two signals each after squaring the components. CONSTITUTION:The ADC2 samples the test signal SC by a frequency four times that of the sinusoidal wave signal Sb, and then samples the sinusoidal wave signal Sb four times during one period. In adding the square of each instantaneous value of adjacent sampling points, the value squaring the amplitude is obtained. The signal is operated by using a multiplier 13, a latch 14 and an adder 15, an output of the adder 15 is converted into an analog signal and displayed on an oscilloscope or the like, the DG of the ADC2 is obtained from a scale of the oscilloscope.
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