| 摘要 |
PURPOSE: To provide sufficient integration time without increasing circuit area. CONSTITUTION: By the change of a voltage applied to an input terminal In, the potential of the emitter of transistors 11 and 12 is changed. Thus, either one of the trarasistors 11 and 12 is turned to an ON state and the other is turned to an OFF state. At the time of the ON state, the transistors 11 and 12 respectively perform an amplification operation and perform discharging to a capacitance 2. For instance, when the transistor 12 is in the ON state, the transistor 12 makes a current for which the current made to flow to a base is amplified flow to the collector of the transistor 12. The base current of the transistor 12 is the charging current of the capacitance 2 and is 1/ (the current amplification factor of a collector current). That is, the base current of the transistor 12 is made smaller than the charging current of the capacitance 2 at the time of directly connecting a resistor and the capacitance 2 and sufficient charging time is secured. The potential corresponding to the charging conditions of the capacitance 2 is outputted from an output terminal Out. |
