Short-circuit protected power supply circuit

A short-circuit protected power supply circuit, comprising:

• a switching power supply comprising a synchronous rectifier, an output inductor, an output capacitor, and an output node, the synchronous rectifier responsive to a synchronous rectifier control signal to selectively switch between an ON state and an OFF state, the output inductor and output capacitor electrically connected in series with each other to form a series LC circuit that is electrically connected in parallel with the synchronous rectifier, the output node located between the output inductor and output capacitor;
• an inverting Schmitt trigger circuit coupled to the output node and configured, upon a voltage magnitude at the output node being less than a predetermined voltage magnitude, to cause the synchronous rectifier control signal to switch the synchronous rectifier to, or keep the synchronous rectifier in, the OFF state;
• a NOR-logic circuit coupled between the Schmitt trigger circuit and the synchronous rectifier;
• and
• a diode coupled in series between the Schmitt trigger circuit and the output node, the diode configured to conduct when the voltage magnitude at the output node is less than the predetermined voltage magnitude.

A short-circuit protected power supply circuit, comprising:

• a switching power supply comprising a synchronous rectifier, an output inductor, an output capacitor, and an output node, the synchronous rectifier responsive to a synchronous rectifier control signal to selectively switch between an ON state and an OFF state, the output inductor and output capacitor electrically connected in series with each other to form a series LC circuit that is electrically connected in parallel with the synchronous rectifier, the output node located between the output inductor and output capacitor;
• and
• short-circuit sense/protection circuit coupled to the output node and configured, upon a voltage magnitude at the output node being less than a predetermined voltage magnitude, to cause the synchronous rectifier control signal to switch the synchronous rectifier to, or keep the synchronous rectifier in, the OFF state, the short-circuit sense/protection circuit including:
• an error amplifier configured to compare the voltage magnitude at the output node to a first reference voltage and supply an error output signal based on the comparison, and
• a comparator circuit coupled to receive the error output signal and a second reference voltage, the comparator configured to compare the error output signal and the second reference voltage and, based on the comparison, to selectively cause the synchronous rectifier control signal to switch the synchronous rectifier to, or keep the synchronous rectifier in, the OFF state.