Wake up management circuit for a switching converter and related wake up method

A wake up method for a switching converter, said switching converter being configured to convert an input signal to a regulated output signal by at least one switch and comprising a transformer with a primary winding coupled with an input terminal and a secondary winding coupled with an output terminal, the method comprising:

• driving the switch of the switching converter by forcing the switching on of the switch with wake up pulses when the switching converter operates in a burst mode, wherein the driving step comprises:
• setting a first peak value of the current of the primary winding,
• receiving cycle by cycle sampled voltage values of the signal (Vaux) representative of the demagnetization of the transformer,
• comparing cycle by cycle the sampled voltage value with at least one voltage threshold;
• and
• comparing cycle by cycle the sampled voltage value with the preceding sampled voltage value;
• and
• in response to the comparings, maintaining the first peak value of the current of the primary winding or setting a new peak value of the current of the primary winding of the transformer.

A control apparatus for a switching converter configured to convert an input signal to a regulated output signal using at least one switch and a transformer with a primary winding coupled with an input terminal and a secondary winding coupled with an output terminal, said control apparatus comprising:

• a control circuit configured to drive said switch when the switching converter operates out of burst mode, wherein the control apparatus comprises a wake up management circuit, said wake up management circuit configured to drive said switch when the switching converter operates in burst mode, said wake up management circuit configured to:
• receive a signal representative of a demagnetization of the transformer;
• force by wake up pulses the switching on of the switch of the switching converter when the switching converter operates in a burst mode;
• and
• receive cycle by cycle sampled voltage values of the signal representative of the demagnetization of the transformer, and comprising:
• a setting circuit configured to set a first peak value of the current of the primary winding;
• and
• a comparison circuit configured to compare cycle by cycle the sampled voltage value with at least one voltage threshold and compare the sampled voltage value with a preceding sampled voltage value and, as a response, maintain the first peak value of the current of the primary winding or set a new peak value of the current of the primary winding of the transformer.