| 摘要 |
PURPOSE:To enable automatic level adjustment, by setting the amplification factor of a variable amplification factor type amplifier according to the peak value of an input analog signal to an A/D converter. CONSTITUTION:The maximum peak value of an input analog signal Si is held at a peak hold circuit 1. This maximum peak value is converted into a digital value with an A/D converter 2. This digital signal is held at a latch circuit 3 and the output of this circuit 3 sets the amplification factor of the variable amplification type amplifier. This amplifier 4 amplifies the signal Si. In this case, the output analog signal So output at the post stage sets the amplification factor of the amplifier 4 so that it is equal to the maximum level effective to the characteristics of the poststage circuit. Thus, automatic level adjustment can be made. |
