| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an amplifier circuit capable of controlling a gain so that the amplitude of an output signal changes desirably when amplifying an input signal while changing the gain so that the amplitude of the output signal approaches a prescribed reference value. <P>SOLUTION: The amplifier circuit detects the amplitude of the output signal outputted by a variable gain amplifier 4, and changes the gain of the variable gain amplifier 4 so that the amplitude of the output signal approaches the prescribed reference value based on the detected amplitude of the output signal. In this case, the gain of the variable gain amplifier 4 is changed by the amount of change decided according to the detected amplitude of the output signal. <P>COPYRIGHT: (C)2009,JPO&INPIT |
