| 摘要 |
PURPOSE:To reduce the area of an external circuit, and also, to inhibit the influence of an external noise by integrating a source follower circuit for driving an FET of a sensor part, a differential amplifier for inputting each source potential and a differentiating circuit. CONSTITUTION:A source follower circuit 2 supplies a constant-voltage and a constant-current to between a drain 5 and a source 7 of an enzyme film (EN) FET, and between a drain 6 and a source 8 of an (RE) FET for reference, respectively and drives the ENFET and the REFET. Also, a differential amplifier 3 inputs a source potential difference of the ENFET and the REFET, and a differentiating circuit 4 inputs an output voltage of the differential amplifier 3 and outputs an output speed of a sensor to a signal output terminal 10. In such a way, by integrating an analog circuit required for a semiconductor biosensor to one chip, an external circuit becomes unnecessary, an area of the external circuit becomes unnecessary, and also, the influence by an external noise is suppressed to the minimum. |
