Voltage converting circuit having parallel connected switching devices

Abstract

The invention relates to a voltage converting circuit () having:—an input terminal () for connection to a varying voltage or current source, and an output terminal () with a supply voltage,—an inductive element () being with a first terminal connected to the input terminal and with a second terminal to a capacitive element () and to the output terminal (), the capacitive element () being with one terminal connected to a reference voltage (),—a first switch () being with a first terminal connected to the second terminal of the inductive element (), and with a second terminal to the reference voltage (), the first switch () comprising a gate electrode () for opening and closing of the switch when a control voltage of a first level is applied to the gate,—an oscillator () comprising a power input () connected to the output terminal (), a start-up output () connected to the gate electrode () of the first switch () for supplying a pulse-like signal to the gate electrode () and an oscillator output (), and—a second switch () connected in parallel with the first switch (), the second switch having a gate electrode () connected to the oscillator output (), wherein the first switch () remains opened when the supply voltage at the output terminal () reaches a predetermined level, and the second switch () is operated by the oscillator output () at a second voltage level that is higher than the first voltage level.