A control device for a switching circuit (Q1, Q2) of a resonant converter having an output dc current (lout), said switching circuit (Q1, Q2) comprising at least a half-bridge of at least a first and a second transistor connected between an input voltage (Vin) and a reference voltage, said half-bridge being adapted to generate a periodic square-wave voltage for driving the resonant circuit of said resonant converter, said periodic square-wave voltage oscillating between a high voltage corresponding to the input voltage and a low voltage corresponding to the reference voltage, said control device comprising generating means adapted to generate a periodic square-wave signal (Vpwm) for driving said half-bridge, wherein said control device is configured to operate said resonant converter in a burst mode, characterized in that said control device comprises: - measuring means adapted to measure the phase-shift (Φ, V Φ) between said periodic square-wave signal (Vpwm) generated by said generating means and the current (Is) flowing through the resonant circuit and adapted to halt said half-bridge when said phase-shift exceeds a first phase-shift value (Vth, Φ th), and - further means adapted to make said half-bridge operative again after the half-bridge is halted, wherein said further means comprise: a) first means (S/H) having a first input signal (Vx) which is representative of the difference between the output voltage (Vout) from the resonant converter and a further reference voltage (Vref) and adapted to sample said first signal (Vx) by providing a second signal (Vxc), and b) second means adapted to compare said first and second signals and to send an activation signal (reset) of the half-bridge (Q1, Q2) when the first signal (Vx) exceeds the second signal (Vxc) by a prefixed quantity. - measuring means adapted to measure the phase-shift (Φ, V Φ) between said periodic square-wave signal (Vpwm) generated by said generating means and the current (Is) flowing through the resonant circuit and adapted to halt said half-bridge when said phase-shift exceeds a first phase-shift value (Vth, Φ th), and - further means adapted to make said half-bridge operative again after the half-bridge is halted, wherein said further means comprise: a) first means (S/H) having a first input signal (Vx) which is representative of the difference between the output voltage (Vout) from the resonant converter and a further reference voltage (Vref) and adapted to sample said first signal (Vx) by providing a second signal (Vxc), and b) second means adapted to compare said first and second signals and to send an activation signal (reset) of the half-bridge (Q1, Q2) when the first signal (Vx) exceeds the second signal (Vxc) by a prefixed quantity. a) first means (S/H) having a first input signal (Vx) which is representative of the difference between the output voltage (Vout) from the resonant converter and a further reference voltage (Vref) and adapted to sample said first signal (Vx) by providing a second signal (Vxc), and b) second means adapted to compare said first and second signals and to send an activation signal (reset) of the half-bridge (Q1, Q2) when the first signal (Vx) exceeds the second signal (Vxc) by a prefixed quantity.