What is the difference between LT8648SJ and LT8648SH?The contents of Note 2 are as follows.I did not explain the difference
LT8648SJ and LT8648SH are guaranteed over the full –40°C to 150°C operating junction temperature range. High junction temperatures degrade operating lifetimes. Operating lifetime is derated at junction temperatures greater than 125˚C. The junction temperature (TJ, in °C) is calculated from the ambient temperature (TA in °C) and power dissipation (PD, in Watts)according to the formula:TJ = TA + (PD • JA)where JA (in °C/W) is the package thermal impedance..
ADI Power by Linear’s production lots go through a rigorous outgoing electrical quality tests that include 100% tested after packaging at 25C to all datasheet’s electrical characteristic. Furthermore, each production lot is sample testing at hot and cold junction temperatures to some of the datasheet’s electrical characteristic as noted by red dot, . It is important to note that if at any point a single part fails during sample testing, the lot will be 100% tested. The J-grade and H-grade products have a different sampling plan at these junction temperatures.
Obviously, the H-grade products provide a lower time zero failure rate and as such are priced higher than J-grade devices. Regardless, both grades are guaranteed to meet performance specification by sample testing rather than typical “assured by design, characterization and correlation with statistical process control” of our competition.