vca821 agc输出随输入变化

按照如图所示搭建的电路，Vref=2V;实际测试时输入8M，0.1Vpp左右信号时,输出随输入幅值变化而变化，求解，求助。

AGC LOOP
In the typical AGC loop shown in Figure 81 , the OPA695 follows the VCA821 to provide 40dB of overall gain. The output of the OPA695 is rectified and integrated by an OPA820 to control the gain of the VCA821. when the output level exceeds the reference voltage (V REF ), the integrator ramps down reducing the gain of the AGC loop. Conversely, if the output is too small, the integrator ramps up increasing the net gain and the output voltage.

你需要调整一下参数来适应你的应用电路

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