| 摘要 |
PURPOSE:To eliminate the error of a signal output by providing a compensating circuit cancelling leakage current of a reset MOSFET to an input terminal of an operational amplifier circuit of a charge integration type signal detecting circuit. CONSTITUTION:In a charge integration type signal detecting circuit where a charge storage capacitor 1 and a reset MOSFET2 are connected in parallel between input and output terminals of an operational amplifier circuit 3, the compensation circuit 4 comprising a compensation transistor 5, gate bias supply power supply 6 and a substrate bias supply power supply 7 is provided between input and ground of the operational amplifier circuit 3 to correct the leakage current of the reset MOSFET2. The compensation transistor 5 uses an the resetting MOSFET2 and the MOSFET of opposite conduction type and the power supplies 6, 7 are adjusted before the signal detection. The reverse current of a diode can be used as the compensation element. |
