US Patent No. 10,485,063

POWER SUPPLY CIRCUIT, AND RELATED LIGHTING SYSTEM AND METHOD FOR OPERATING A POWER SUPPLY CIRCUIT


Patent No. 10,485,063
Issue Date November 19, 2019
Title Power Supply Circuit, And Related Lighting System And Method For Operating A Power Supply Circuit
Inventorship Giaime Ugliano, Martellago (IT)
Maurizio Minuti, Belluno (IT)
Assignee OSRAM GmbH, Munich (DE)

Claim of US Patent No. 10,485,063

1. 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.