After I send a AC sine to the positive input pin, the DC offset adds to the AC sine. Then,the output of the amplifer is saturated，it is VCC or VEE
Could you share your complete schematic and the results you got? Thank you!
When the pin3 is floating, I test a 2V DC offset in pin3. If I remove the R31 and R32, the 2V DC offset can be still tested.
When I send a sine with 800mv VPP and 0V DC offset to the pin3, the 2V DC offset adds to the sine and pin1 outputs 3.3V DC .
If the input is floating, it can be anywhere.
For a 190 MHz gbw op amp, unless you have a very clean pc board layout and
adequate bypassing, it is oscillating. Put a scope on the output.
The frequency of sine I send to the positive input pin is 1.36Mhz.
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