| 摘要 |
PURPOSE:To measure the characteristics of the coder other than a DC input, by inputting a sine wave to the coder via a converter, performing a sampling, and measuring the characteristics of the coder. CONSTITUTION:The sine wave is generated by a signal generating circuit 11, converted into a specified level by a level converter 12, and inputted to the coder 13. The output of the coder 13 is compared with the output of a digital value code generator 15 in a digital comparator 14. The level of the input signal to the coder 13 changes in the sine wave shape, and is sampled by a specified repeating frequency. The output of the coder is formed in this way. The result of the specified sampling number is stored in a signal processing circuit 16. If the output is larger than a set code, a feedback signal is fed to the converter 12, and amplitude of the input to the coder 13 is decreased. If the feedback signal is not present, the amplitude is increased. This operation is repeated several times, and the output characteristics are measured. Therefore, the characteristics other than the DC input can be measured. |
