Power supply circuit, and related lighting system and method for operating a power supply circuit

A power supply circuit comprising:

• two output terminals for providing a current;
• a current generator configured to generate a regulated current, wherein said current generator comprises:
• a switching stage comprising one or more first electronic switches and one or more inductors, said switching stage being configured to provide said regulated current as a function of one or more drive signals,
• a current sensor configured to detect at least one feedback signal indicative of said regulated current provided by said switching stage, and
• a regulator circuit configured to generate said one or more drive signals for said switching stage as a function of said at least one feedback signal;
• wherein the regulator circuit comprises a comparison circuit such that the regulated current comprises a ripple and the regulated current varies periodically between an upper threshold and a lower threshold;
• a second electronic switch configured to selectively short circuit the output of said current generator as a function of a further drive signal;
• and
• a control circuit configured to generate said further drive signal for opening or closing selectively the second electronic switch;
• wherein said current generator is configured to activate or deactivate the generation of said regulated current as a function of an enable signal, and said control circuit is configured to generate said enable signal and said further drive signal, in order to repeat periodically the following steps:
• after a first time-interval, activating said current generator;
• after a second time-interval, opening the second electronic switch, wherein the duration of the second time interval ranges from 0.8 to 1.5× of the time required until the regulated current reaches the upper threshold after an activation of the current generator;
• after a third time-interval, closing the second electronic switch, and
• after a fourth time-interval, deactivate said current generator.