Amplifier using Time variable gain unable to amplify beyond certain limit

Hi Folks

I am using a variable gain amplifier AD605 and providing it a time variable gain as a ramp voltage(VGN) from 0 to 2.5V such that it will amplify the input 140mVpp within some milliseconds. But the problem here is that the input amplifies until a certain point and then it remains at that level thereafter without any further amplification observed as shown in the picture attached. I am not sure what's the reason behind this, is it the output range of the amplifier or any other reason. CAN ANYONE SUGGEST SOME USEFUL POINTS.



CHANNEL 1 INPUT AND CHANNEL2 OUTPUT
IMAGES TEK00189-192 SHOW THE PATTERN OF INCREASING OUTPUT AND TEK00202 IS THE IMAGE ZOOMED OUT IMAGE SHOWING NO CHANGE IN OUTPUT AFTER A CERTAIN LIMIT(CHANNEL2).
Datasheet AD605:-

https://www.analog.com/media/en/technical-documentation/data-sheets/AD605.pdf

Clearly a case of output saturation.

Read the datasheet. Pay attention to maximum output voltage.

Thanks FvM for your reply

I went through the data sheet but a bit unsure about what does this parameter Output Signal Range actually means. Can you please help me explaining this thing and how it causes amplifier to saturate coz i need to document it why it happens.

jimmykk said:

I went through the data sheet but a bit unsure about what does this parameter Output Signal Range actually means. Can you please help me explaining this thing and how it causes amplifier to saturate

Click to expand...

With a +5V supply its output can go down and saturate to 2.5V - 1.5V= +1V and it can go up and saturate to 2.5V + 1.5V= +4.0V when it has a 500 ohm load. Yours is a little better going down to about +0.75V and going up to about +4.25V.