In an embodiment, A switched-mode power supply includes: a first node; a second node configured to receive a DC input voltage; a third node configured to receive a reference voltage; first and second switching transistors; a first circuit configured to control the first switching transistor; and a second circuit configured to control the second switching transistor, wherein the switched-mode power supply is configured to deliver a regulated output voltage at the first node from the DC input voltage, and wherein the first and second circuits are configured to be powered from the output voltage.