基于51单片机的，通过DA TL5615输出电压，控制宽带高增益压控放大芯片AD603的放大倍数。放大倍数由DA输出电压与AD603的另一固定的参考电压之差共同决定-Based on 51 single-chip, through the DA TL5615 output voltage, control voltage-controlled high-gain broadband amplifier chip AD603 magnification. Magnification with the AD603 output voltage by the DA' s another difference between a fixed reference voltage common decision