analog - Need an optocoupler for getting directly proportional output galvanically isolated from the DC input

I want to use an optocoupler to linearly step down a DC voltage which willy vary from 0V to 400V. That is, I want the output to be directly proportional to the input and I want it to be galvanically isolated from the input

Now, for this purpose I used IL300 and MCT2E earlier. The problem with IL300 was that the slope (linearity factor) varied across different samples of the IC. I can not allow that to happen. And the problem with MCT2E was that the linearity lived only up to a particular value of input ad the output tended to get saturated after that. I realize that changing Rs might have solved this problem, but the saturation couldn't be eliminated quite very properly. Now, I'm looking for some other optocoupler for this purpose. I have shortlisted LTV 817 for this purpose but I'm not sure how it is going to perform. So, I want to select atleast two more ICs for this purpose and then test all of them to select the best one.

What I require from the IC:

1. Directly proportional output for a DC input varying from 0-400V.


2. Galvanic Isolation between input and output.


3. Output to vary linearly with the input, between 0 to 12V.

Can you guys please suggest me some optocouplers that will help me solve this purpose? Note: There might be devices other than optocouplers, available for this purpose, and I welcome suggestions regarding them as well, but I prefer optocouplers.