Figure 18. Short-circuit (with OVT) during ON state

Figure 19. Switching on short-circuit (with OVT)

7.2

Thermal protection

The device is protected against overheating due to overload conditions. During driving period, if the output is

overloaded, the device suffers two different thermal stresses, the first one related to the junction, and the second

related to the case.

The two faults have different trigger thresholds: the junction protection threshold (TJSD) is higher than that of the

case protection (TCSD). Generally, the first protection that is activated in thermal stress conditions is the junction

thermal shutdown. The output is turned off when the temperature is higher than the related threshold and turned

back on when it falls below the reset threshold (TJR). This behavior continues while the fault on the output is

present.

If the thermal protection is active and the temperature of the package increases over the fixed case protection

threshold, the case protection is activated, and the output is switched off and back on when the junction

temperature of each channel in fault and case temperature are below the respective reset thresholds.

Figure 20. Thermal protection flowchart

ISO808A, ISO808A-1

Thermal protection

DS14170 - Rev 1

page 21/38