TEMPERATURE DEPENDENT CURRENT LIMIT CONTROL FOR FAST-CHARGING AND SAFE OPERATING AREA (SOA) PROTECTION

An apparatus includes a power transistor to conduct a load current from a supply voltage node to an output node and a current sense circuit coupled to the power transistor. The current sense circuit generates a current sense current proportional to the load current. A temperature sense circuit is included to generate a temperature sense voltage proportional to the temperature of the power FET. A thermal limit circuit is coupled to the temperature sense circuit. A current limit circuit is coupled to the current sense circuit and to the thermal limit circuit. The current limit circuit generates a control signal on a current limit circuit output node. The control signal is responsive to the current sense current and to a first current from the thermal limit circuit. The current limit circuit output node is coupled to a control input of the power transistor.