I'm in a bit of a bind.
On one design we have a TEC that has a bit of a lead time and was hoping to substitute it in case we run out. Dimensions, delta-T and everything else are the same but the voltage ratings are slightly different. The old part has a maximum voltage rating of 4.3V, while the new one is 3.8V
Now, the TEC driver does have a 5V supply but it only peaks up that high very briefly at initial boot, then it's just temperature stabilizing. It's regulating the temperature of a small piece of metal. Steady state operation is <1V.
I would say that current 4.3V TEC is a bit under-speced and it would be ideal if the driver was running off of 3.3V.
How bad is it for the TEC to receive a voltage larger than it's rating? With motors you can overdrive them a bit as long as it isn't prolonged. Am I playing with fire by checking off that the 3.8V TEC is a suitable substitute in a pinch? It looks like it's driving fine, but could the voltage rating cause serious issues down the line?