| 摘要 |
PURPOSE:To attain the measurement of an input/output characteristic in a short time by providing a differential amplifier where a digital input is given to a D/A converter to be measured and a reference D/A converter, an output level of both converters is compared and the result of comparison is given to an IC tester as a digitized output. CONSTITUTION:A central processing unit 5 gives a measuring command signal to a digital measuring unit 4, which gives digitized input for measurement to both D/A converters 1, 2 in response to this signal. This digitized input is given sequentially to the converters 1, 2 by the number of combinations of 2n. The converters 1, 2 give an analog output in response to the inputted digitized input to each input section of a differential amplifier 8. The differential amplifier 8 gives a prescribed difference voltage to the measuring unit 4 when the input/output characteristic of the D/A converter 1 to be measured is within the specified range. The measuring unit 4 makes discrimination by internal discriminating devices A, B and the result of discrimination that the D/A converter 1 to be measured is a non-defective converter in this case is stored in a storage section C. |
