Tool/software:
Hi, I refer to SN65MLVD2DRBT (https://www.ti.com/product/SN65MLVD2/part-details/SN65MLVD2DRBT?keyMatch=SN65MLVD2DRBT&tisearch=universal_search&usecase=OPN)
I understand from the datasheet that the device is characterised for operation up to +85degC. I suppose this is the ambient air temperature.
I would like to check if a maximum operating junction temperature is available?
Thank you
Hi Benedict,
So it isn't directly spec'd but you can derive it to be 125C.
From this table we can derive R_theta_JA - which is the thermal ambient to junction impedance.
There are two values here - one for a Low-K and one for a high-K PCB.
If you take the inverse of the derating factor above TA = 25C - that is the R_theta_JA value.
So for Low-K R_theta_JA = 357.14 C/W
For High-K R_theta_JA = 151.06 C/W
We also know that:
TJ = TA + P*R_theta_JA
and we are also given power ratings
If we plug in the max ambient temperature allowed + the max power dissipation of IC from chart we can get the max TJ - or the max junction temperature.
So
High K PCB --> TJ = 85 + 112mW * 357.14 = 125C
Low K PCB --> TJ = 85 + 264mW * 151.06 = 125C
So since our max power ratings and the thermal to ambient junction impedance are spec'd we can derive max allowable junction temperature to 125C for this device.
Best,
Parker Dodson
