( Tj MAX )
Maximum allowable transistor junction temperature. Silicon transistors
normally have a maximum allowable junction temperature of 200 C. Devices
packaged in plastic may have this value reduced to 150 C.
Tj max is an industry standard number based on projected lifetime; in most
cases it does not represent a boundary to catastrophic failure of the transistor.
Operation at temperatures above Tj max is not recommended as it will result in
greatly decreased lifetimes since operating life is exponentially proportional to
the inverse of the operating temperature.
Tj max may also be familiarly (though technically incorrectly) used to
represent the maximum channel temperature (Tch) of a GaAs FET.