Switched-mode power supply circuit.

摘要

A switched-mode power supply circuit for converting a DC input voltage into a DC output voltage comprises a series arrangement of a controllable power switch and an inductive element coupled between the input voltage terminals, control means for rendering the power switch alternately conducting and non-conducting and a rectifier coupled to the inductive element for making the output voltage available, the inductive element and a capacitor coupled thereto forming a part of a resonant circuit in the periods of time when the switch and the rectifier are currentless, in which resonant circuit a voltage oscillation is then present. The circuit further comprises means for interrupting the oscillation present in the resonant circuit at an instant when the voltage across the inductive element or the current through the capacitor is substantially zero. This measure ensures that the dissipation in the circuit is reduced or that the circuit is synchronized.