Attention to Internet Explorer users: ROHM website does not recommend browsing in IE 11. Please use latest browser to ensure the best performance on ROHM website.
Yes, ROHM's TCs must be derated at temperatures exceeding 85ºC (see graph below). Since the voltage supplied to the TC can take many forms and include transients (and possible overshooting), enough margin must be designed in. Many TC manufacturers are recommending using the TCs at 50% of the rated voltage.