| 摘要 |
PURPOSE:To prevent output compliance caused by the fluctuation of an output voltage to evaluate and select a D/A converter with high accuracy, by evaluating the D/A converter to be evaluated by adjusting the sum of the outputs of the D/A converter to be evaluated and another D/A converter which is used as a reference to become constant. CONSTITUTION:By commonly connecting the output of a current output type D/A converter 2 which is used as a reference and another current output type D/A converter 1 to be evaluated and successively inputting complementary numeral strings to the two D/A converters 1 and 2, the output fluctuation at the common connecting point is measured. Namely, the converter 1 performs its D/A conversion from a lower level to a higher level and the converter 2 makes D/A conversion from a higher level to a lower level, then, the sum of the output currents of the converters 1 and 2 is converted into a voltage through a resistance 3. If the D/A converter 1 to be evaluated is free from distortion, an output voltage VOUT must be maintained at a fixed level and, therefore, when the output voltage VOUT is observed, the D/A converter 1 can be evaluated.
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