WAVEFORM SAMPLING CIRCUIT

PURPOSE:To realize the high-speed waveform sampling circuit made into IC at a high speed and with high accuracy by constructing it to output a voltage to be measured and a voltage change corresponding to time width to be measured alternately from the output of a hold amplifier. CONSTITUTION:A voltage to be measured signal VIN is held in a hold capacitor CH at the point of time of sampling in a voltage measuring mode, and only the time width to be measured from a trigger point to a sampling point is discharged by a constant current source after holding a standard voltage signal VTR in the hold capacitor CH in a time measuring mode. Namely, the voltage to be measured and the time width to be measured, corresponding to the voltage change, are constructed to be alternately outputted from the output of a hold amplifier 5. Therefore, a track hold circuit and an AD converter connecting to this can be shared in voltage measuring and time measuring. Thus, the high- speed waveform sampling circuit made into IC at a high speed and with high accuracy can be easily realized.