Current limiting is accomplished by internally limiting the drive to the output transistors. The output can supply the limited current continuously, unless the die temperature rises to 150°C and initiates thermal shutdown. With adequate heat dissipation, and use of the lowest possible supply voltage, the OPA455 can remain in current limit continuously without entering thermal shutdown. The best practice is to provide proper heat dissipation (either by a physical plate or by airflow) to remain well below the thermal shutdown threshold. For longest operational life of the device, keep the junction temperature below 125°C.