| 摘要 |
PURPOSE:To elevate the measuring accuracy, by returning an output signal of a semiconductor element to be measured to an input terminal of the semiconductor element being measured with a feedback circuit having an information holding function to measure characteristics of the semiconductor element being measured. CONSTITUTION:First, a switch 2 is connected to the position (a) and a switch 8 is opened. A reference voltage of a DC reference voltage source 1 is applied to a semiconductor measuring element 3. Then, a feedback frequency n-1 is inputted into a setting circuit 12 manually and a reset signal SR is provided to memories 5 and 6 and a counter 11. A clock signal S0 from a clock generator 10 is applied to an A/D converter 4 and a delay circuit 16 and an analog output signal VDA of a D/A converter 7 is fed back to the input of the element 3 through a switch 2 to be controlled by a comparison circuit 14. When the feedback frequency set for the setting circuit 12 equals the contents of a counter 11, the feedback operation is stopped and the output voltage of the element 3 is applied to a DC voltometer 9 through a switch 8 to achieve a higher measuring accuracy.
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