A power-supply circuit may include a current generator configured to generate a regulated current. The current generator may include a switching stage, a current sensor, and a regulation circuit configured for driving the switching stage as a function of a feedback signal supplied by the current sensor.The power-supply circuit may further include an electronic switch configured to shortcircuit selectively the output of the current generator as a function of a drive signal, and a control circuit configured to generate the drive signal for opening or closing selectively the electronic switch.In particular, the current generator is configured to activate or de-activate generation of the regulated current as a function of an enable signal, and the control circuit is configured to generate the enable signal and the drive signal in such a way as to synchronize the ripple in the regulated current with the further drive signal.