| 摘要 |
<p>PURPOSE: To obtain a current amplifier having substantially flat frequency response characteristic within a prescribed operation range by allowing the current amplifier to correspond to the reduction of gain in the frequency response characteristic of a 1st operational amplifier at fixed gain until the frequency response characteristic of a 2nd stage reaches prescribed frequency. CONSTITUTION: The frequecy characteristic of a 2nd operational amplifier IC2 is determined by a resistor R17 and a capacitor C10. The feedback loop of a 3rd operational amplifier IC3 is constituted of a series circuit consisting of a variable resistor VR1 and a resistor R23 and connected between an output (terminal pin 6) and an inverted input (terminal pin 2). The feedback loop is connected to an earth through a resistor R24 and a capacitor C8. The frequency characteristic of the amplifier IC3 is determined by the resistor R24 and the capacitor C8. The output of the current amplifier constituted of two stages is extracted from an output terminal O/P connected to the output (terminal pin 6) of the amplifier IC3 through a resistor R25.</p> |
