| 摘要 |
<p>PURPOSE:To decrease the number of operational amplifiers by connecting a resistor between a signal input and a non-inverting/inverting input terminal and between an output terminal and a negative input terminal respectively, connecting a resistor and a capacitor in series between the output terminal and ground, and connecting a capacitor between the connection of the capacitor with resistor and the non-inverting input. CONSTITUTION:Resistors R9, R10 are connected respectively between the signal input and the non-inverting/inverting inputs of the operational amplifier 7. A resistor R11 is connected between an output and the inverting input of the operation amplifier 7, the resistor R12 and the capacitor C6 are connected in series between the output and ground of the operational amplifier 7, and a capacitor C5 is connected between the connecting point of the capacitor C6 with the resistor R12 and the non-inverting input of the operational amplifier 7. A filter is constituted by the operational amplifier 7 when the condition of (C5+C6)/C5= R9R11/R10R12 is satisfied.</p> |
