I have a question regarding the handling of the LTC4120's THERMAL FAULT status.
We are wirelessly charging a battery using the LTC4125 in an open loop mode. We cannot close the loop using feedback because our distance can be too great (up to 25mm). We are getting a THERMAL FAULT status from the LTC4120 when charging at elevated ambient temperatures. However, when this occurs, our temperatures rise even more because the 4120 pauses the charging and the transmitter is still transmitting power. This is actually the worst case condition for generating heat in our device, so the device never cools down. The heat is being generated in the charging coil front end components (mostly the zener diode limiting the rectified input).
Does anyone have any suggestions as to how to mitigate this runaway thermal problem at the receiver end?