In a DC/DC converter comprising a transformer (10) having a primary winding Np and at least first and second secondary windings Ns1 and Ns2; a main output path connecting the first secondary winding to a main output Vp and comprising a synchronous rectifier circuit, a first inductor L1, and a first capacitor C1; and an input path connecting a DC supply voltage Ve to the primary winding and including a switch circuit (12) controlled by a first pulse width modulator PWM1 to regulate the main output voltage by switching the current in the primary winding, there is provided an auxiliary output circuit connecting the second secondary winding to an auxiliary output Va and comprising an auxiliary rectifier path having a control switch M5, a free-wheel switch M6, a rectifier switch M3, a second inductor L2, and a second capacitor C2; and a second pulse width modulator PWM2 connected to the control switch M5 and to the free-wheel switch M6 to control a conduction interval of said switches in order to regulate the auxiliary output independently of the main output, the rectifier switch M3 being controlled synchronously with the synchronous rectifier circuit of the main path.