Protection circuit, corresponding system and method

A system for supplying electrical power to a load, the system comprising:

• a power transistor configured to be coupled between a battery power supply and the load;
• and
• a protection circuit comprising:
• a driver circuit coupled to a driving electrode of the power transistor;
• a switch having a switch output coupled to the driver circuit;
• and
• safe operating area monitoring circuitry coupled to the switch and configured to:
• receive as input at least a current value proportional to a current flowing through the power transistor;
• control operation of the power transistor, with respect to a safe operating area as a function of transistor thermal behavior information and the at least the current value proportional to the current flowing through the power transistor, by controlling a value of a junction temperature of the power transistor;
• and
• output an output signal that controls on and off states of the driver circuit via the switch to obtain a given behavior in time of the junction temperature of the power transistor within the safe operation area.

A method of controlling a power transistor coupled between a battery power supply and a load, the method comprising:

• receiving, by safe operating area monitoring circuitry of a protection circuit, as input at least a current value proportional to a current flowing through the power transistor;
• controlling, by the safe operating area monitoring circuitry, operation of the power transistor, with respect to a safe operating area as a function of transistor thermal behavior information and the at least the current value proportional to the current flowing through the power transistor, by controlling a value of a junction temperature of the power transistor;
• and
• outputting, by the safe operating area monitoring circuitry, an output signal that controls on and off states of a switch coupled to a driver circuit coupled to a driving electrode of the power transistor, to obtain a given behavior in time of the junction temperature of the power transistor within the safe operating area.