As I know IC has little consumption and close to case temperature.
But what's the max power ic can afford ? Maybe 0.5W? it can help me estimate the temperature margin.
As datasheet noted LT4295 TEMPERATURE RANGE = -40C~85C, Does it mean "Junction Temperature" ?
What will LT4295 do when junction temperature over 85C~150C.
As I know Junction temperature can exceed 150°C when overtemperature protection is active.
Kindly help me with it.
Thanks a lot.
The LT4295 consumes very little power. Its bias current is 2mA (max) at 60V input. This sets power consumption of the IC at 60V to 120mW. θJC = 3.4°C/W and θJA = 43°C/W with a JEDEC 4-layer board for this package. A rough estimate for junction temperature is 0.4°C warmer than the case and 5°C warmer than ambient.
The max operating junction temperature is 85°C for I-grade and 125°C for H-grade parts. Using the estimates above; I-grade parts should operate up to 80°C ambient and H-grade parts should operate up to 120°C ambient. Ambient temperatures that exceed this may affect reliability and lifetime of the part.