Hi
Now i am working on a project. i use a AD810 in my work after AD810 i have amplifier and buffer circuit. i saw a noise on output after a lot searching i found out AD810 is noise source. because when i remove AD810 noise will be neglected. i show output of circuit in a picture when the main signal is not presented. how can i eliminate this oscillation. oscillation frequency is 15Mhz and its amplitude is about 100mv p-p.
thanks
An AD810 is a video opamp with a full power bandwidth of 16MHz. The opamp has gain up to hundreds of MHz.
If your pcb layout has a small amount of capacitance from its output to its input or through the power supply connection (or even through the ground connection) then sure the circuit will oscillate.
As a current feedback OP, the AD810 allows easy adjustment of it's loop gain for stable operation.
But a wrong dimensioning of Rf can also cause oscillations. Capacitive load without an isolation
resistor is another possible source of instability, apart from the layout issues mentioned by Audioguru.