SLLSEA5C March 2012 – March 2019 ISO7421E-Q1
Safety limiting intends to prevent potential damage to the isolation barrier upon failure of input or output circuitry. A failure of the IO can allow low resistance to ground or the supply and, without current limiting, dissipate sufficient power to overheat the die and damage the isolation barrier potentially leading to secondary system failures.
|Is||Safety input, output, or supply current||θJA =212°C/W, VI = 5.5 V, TJ = 170°C, TA = 25°C||112||mA|
|θJA =212°C/W, VI = 3.6 V, TJ = 170°C, TA = 25°C||171|
|Ts||Maximum Case Temperature||150||°C|
The safety-limiting constraint is the absolute maximum junction temperature specified in the absolute maximum ratings table. The power dissipation and junction-to-air thermal impedance of the device installed in the application hardware determines the junction temperature. The assumed junction-to-air thermal resistance in the Thermal Characteristics table is that of a device installed on a High-K Test Board for Leaded Surface Mount Packages. The power is the recommended maximum input voltage times the current. The junction temperature is then the ambient temperature plus the power times the junction-to-air thermal resistance.