一种低成本AGC电路研制

Development of A Low-cost AGC Circuit

在微弱信号检测中，当输入信号变化范围很大时，固定增益放大电路不能满足要求，必须采用自动增益控制（AGC）电路。在对AGC电路进行研究后，提出了一种低成本的AGC电路，仅采用1个LM324集成块。其中，二级运放放大输入信号，一级运放产生控制电压。实验表明，电路增益在43～68dB之间自动变化，AGC控制达到25dB。可作为一般弱信号检测放大电路。

When the input signal range is very big in weak signal detection, fixed gain amplifier circuit cannot meet the requirements, must adopt automatic gain control （AGC） circuit. After the study of AGC circuit, puts forward a low cost of AGC circuit,with a LM324 integration block only, among them, the two stage operational amplifier input signal, the level of op - amp produces the control voltage. Experimental results show that the circuit gain automatic change between 43 dB and 68 dB, AGC control range of 25 dB amp circuit can be used as general weak signal d tion.