Feedback-controlled switched converter for a led load

A feedback-controlled switched converter (101), comprising:

• at least one switch (103);
• output terminals (102a, 102b) for supplying an LED load (102);
• a control unit (104) being supplied with a feedback signal indicating a load current of the LED load (102), wherein the control unit (104) is configured to:
• generate an output signal on the basis of the feedback signal;
• combine the output signal with a periodic modulation signal in order to obtain a control signal, the control signal being configured to set an operation parameter of the at least one switch (103);
• apply the control signal to the at least one switch (103);
• means for enabling/disabling the periodic modulation signal,
• wherein the means for enabling/disabling is configured to enable/disable the periodic modulation signal only at time periods of the periodic modulation signal in which an amplitude of the periodic modulation signal is lower than an amplitude threshold, or
• wherein the means for enabling/disabling the periodic modulation signal is configured to only enable/disable the periodic modulation signal at first time periods of the periodic modulation signal being centered at zero-crossings of the periodic modulation signal, these first time periods being separated by second time periods centered around the peaks of the periodic modulation signal and in which no enabling/disabling of the periodic modulation signal is performed, or
• wherein the means for enabling/disabling the periodic modulation signal is configured to only enable/disable the periodic modulation signal as soon as zero-crossing detection means of the converter indicate a zero-crossing of the modulation signal.