| 摘要 |
PROBLEM TO BE SOLVED: To obtain a digital control system pyroelectric type detected signal sampling circuit which will not produce variations in its output signal by changes in the temperature, and is capable of obtaining precise direct-current output characteristics. SOLUTION: A trigger signal generating unit 10 and a crystal oscillator 11 are incorporated, and a trigger signal TR, a first sampling signal S<SB>1</SB>, and a second sampling signal S<SB>2</SB>which are required are generated. A difference signal is found by a subtraction circuit 50, from a first sampling output signal VS<SB>1</SB>which is controlled by the first sampling signal S<SB>1</SB>and outputted from a first sample and hold circuit 41, and a second sampling output signal VS<SB>2</SB>is controlled by the second sampling signal S<SB>2</SB>and outputted from a second sampling output signal VS<SB>2</SB>, and an output current voltage signal Vout is outputted. Since the influence due to the changes in the temperature on the characteristics of the crystal oscillator 11 is not remarkable, precise result can be obtained. In addition, expensive electronic components which is a part can be substituted by a single circuit, and the cost can be lowered sharply. COPYRIGHT: (C)2004,JPO&NCIPI
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