A switched-mode converter comprising: a first magnetic circuit comprising a first inductive element, coupled to at least one second inductive element and electrically in series with this second element and with a first diode between a first one of two input terminals (21, 23) and a first one of two output terminals; a first switch in series with a third inductive element between a second terminal of the first inductive element and a second input terminal, a common node between the first switch and the third inductive element being coupled to one of the output terminals by a second diode; characterized in that it further comprises: a circuit capable of canceling the voltage across this first switch before its turning-on, and comprising: - a fourth inductive element between said common node and the second diode; and - between the fourth inductive element and the second diode, two branches of connection to the second input terminal, respectively by a resistive element and by a second switch; and - a second magnetic circuit comprising the fourth inductive element coupled to a fifth inductive element, said fifth inductive element being electrically in series with the fourth inductive element and interposed between said branches. a first magnetic circuit comprising a first inductive element, coupled to at least one second inductive element and electrically in series with this second element and with a first diode between a first one of two input terminals (21, 23) and a first one of two output terminals; a first switch in series with a third inductive element between a second terminal of the first inductive element and a second input terminal, a common node between the first switch and the third inductive element being coupled to one of the output terminals by a second diode; characterized in that it further comprises: a circuit capable of canceling the voltage across this first switch before its turning-on, and comprising: - a fourth inductive element between said common node and the second diode; and - between the fourth inductive element and the second diode, two branches of connection to the second input terminal, respectively by a resistive element and by a second switch; and - a second magnetic circuit comprising the fourth inductive element coupled to a fifth inductive element, said fifth inductive element being electrically in series with the fourth inductive element and interposed between said branches. a circuit capable of canceling the voltage across this first switch before its turning-on, and comprising: - a fourth inductive element between said common node and the second diode; and - between the fourth inductive element and the second diode, two branches of connection to the second input terminal, respectively by a resistive element and by a second switch; and - a second magnetic circuit comprising the fourth inductive element coupled to a fifth inductive element, said fifth inductive element being electrically in series with the fourth inductive element and interposed between said branches. - a fourth inductive element between said common node and the second diode; and - between the fourth inductive element and the second diode, two branches of connection to the second input terminal, respectively by a resistive element and by a second switch; and - a second magnetic circuit comprising the fourth inductive element coupled to a fifth inductive element, said fifth inductive element being electrically in series with the fourth inductive element and interposed between said branches.