I know this is a somewhat old post, but there are no responses so I will try. I think that is because the question is too vague.
If you could clear up two points, perhaps someone could formulate an answer.
What it this TC point you are referring to? The only technical reference to a Tc point that I can find is a Curie Temperature, but it does not seem that this is what you are talking about.
Second, there are many forms of LED drivers. Is this a chip? An assembled circuit? Is it packaged? You did say "driver case". If so, how? Can you state the make and model? It may be possible to get a data sheet on it; most electronic components have published data sheets and they can help a lot.
A photo or two may help.