| 摘要 |
PURPOSE:To obtain a high integration degree by converting a data strobe signal into a signal having a time tilt which corresponding to an analog input voltage and detecting a time till which the level of the converted signal reaches the circuit threshold of a coincidence circuit. CONSTITUTION:A first transistor T1 and a capacitor C1 convert the data strobe signal A into the signal having the tilt corresponding to the analog input voltage IN and detect the time till which the level of the converted signal reaches the circuit threshold of an exclusive OR circuit XOR as the coincidence circuit so as to obtain a digital output by counting the clock pulse signals phi of the number corresponding to the detected time by a counting means 13. In this case, if a second analog input voltage Va is set in the maximum value of the first analog input voltage IN, a noncoincident signal is outputted from the coincidence circuit XOR because of the existence of the first transistor T1 when the first analog input voltage IN is the maximum, so that a digital output can be prevented from having a specified value. Thus, the high integration can be obtained with comparatively easy process technique.
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