AD629

You have a high pass,, so the gain increases with increasing frequency

and crosses Bode plot at 90 degrees.

Change 30 pf to 0.1uF and try it.

Harry

Thank you, the oscillation is soluted.

But, The ratio of output to input amplitude is related to the frequency of input signal.

How can I fix the ratio of output to input when the frequency of input signal in my system is constantly changing and the amplitude is greater than 14V?

We need more info.

Supply voltages?

Frequency??  1kHz?  1MHz?  100MHz?

INput signal common mode and amplitude?

Load?

etc.

Harry

We need more info.

Supply voltages?

Frequency??  1kHz?  1MHz?  100MHz?

INput signal common mode and amplitude?

Load?

etc.

Harry