Power supply circuit with short circuit protection

A power supply circuit comprising:

• a switching regulator including an output coupled to a first power supply node;
• a battery node for coupling to a battery;
• a switch coupled between the first power supply node and the battery node;
• a first transistor including a gate coupled to the first power supply node and a source coupled to a reference potential node of the power supply circuit;
• and
• a first current source or a resistive element, coupled between a power supply rail and a drain of the first transistor, wherein after completion of a soft start of a voltage of the first power supply node, an automatic fault protection (AFP) mode is configured to be triggered when the voltage of the first power supply node is less than a threshold voltage of the first transistor.

A power supply circuit comprising:

• a switching regulator including an output coupled to a first power supply node;
• a battery node for coupling to a battery;
• a switch coupled between the first power supply node and the battery node;
• a first transistor including a gate coupled to the first power supply node and a source coupled to a reference potential node of the power supply circuit;
• a first current source or a resistive element, coupled between a power supply rail and a drain of the first transistor;
• a charge pump including a first terminal coupled to the first power supply node and including a second terminal coupled to a second power supply node, wherein the switch is coupled between the second power supply node and the battery node;
• a second transistor including a gate coupled to the second power supply node and a source coupled to the reference potential node;
• and
• a second current source coupled between the power supply rail and a drain of the second transistor.